How to set up Airport Extreme with Charter ARRIS Modem TM902A for the first time for WIRELESS.

Question

How to set up Airport Extreme with Charter ARRIS Modem TM902A for the first time for WIRELESS.
When Charter Tech goes to your site, have them connect the modem up, but do not connect the modem to your iMAC or MacBook Pro.  What you want to do is connect the Airport Extreme to the iMac or MacBook Pro first with the Ethernet Cable. You have to do this to configure via Airport Utility to set up the Base Station Name & Base Station Password.
You will then create/configure a Wireless Network, create your Wireless Password that will be entered on each of your Devices, example, Apple Tv, your iPhone, etc., you want to allow access to your Wireless Network you are creating.
Wireless Security will be -> WPA/WPA2 personal or just WPA2
Enter the Wireless Password you want
Verify the Wireless Password (enter it again)
After it is created you will see it on the Airport Utility window with the name you created for it and to the left, will be a Dot (circle that will be yellow).
Next you then want to unplug the power to the Airport Extreme, and then take the end of the Ethernet cable you unplugged from the iMac or Lap top MacBook Pro and connect it to the back of the Modem.
Next unplug the power cord from the modem and wait about 5 minutes, then plug the power back into the Arris Modem and wait until all lights come back on the modem wait
about 5 minutes, then plug the power cord back to the Airport Extreme and you will see it the light blinking yellow.  Wait about 5 to 10 minutes, during this time Restart you IMAC or MacBook Pro, and once it is back up click on the Airport Utility and you should see on the Airport Utility screen.
For INTERNET to the left the light should be green and you should see the Airport Extreme also appear and the light to the left on the screen should also be green.  If they are, you then should be able to click on the Wireless Symbol on top of bar of the screen and click to select the Wireless Network Name you created.
If you Do Not See the light (Icon) next to INTERNET turn Green, or if you see the Internet Light Green, but the Light (Icon) next to the Airport Extreme is yellow, unplug the power again to the modem and unplug the power again to the Airport extreme and wait about 15 minutes or up to 30 minutes. Then plug the power cord back to the modem wait till all the lights light up then, plug the power cord back into the Airport Extreme and Restart your iMAC or MacBook Pro.
The Airport Extreme light should change from yellow to green. Open up the Airport Utility to see what the indicators are showing they should both be green.  Again select Wireless network you created under the Wireless Icon on the top right of the screen. Open Safari and see if you are able to Route to a web page or the apple site should appear.
WHAT TO DO IF YOUR AIRPORT EXTREME WAS PREVIOUSLY SET UP FOR USE WITH ANOTHER CARRIERS ROUTER OR MODEM.
NOTE:  If you already had your Airport Extreme connected for example, I previously had ATT Uverse and the Airport Extreme was connected to the Wireless Router Model 3801HGV, I disabled the Uverse Wireless and used the Airport Extreme for the Wireless signal in bridge mode, as the Airport extreme Signal is much stronger than the Uverse router, and I was able to obtain a Wireless signal with the Airport Extreme way much better with no signal loss which was very very frustrating with the Uverse router.
Anyhow if you had it hooked up like this, now that you will be using it with the Charter ARRIS Modem TM902A, you will need to reset the Airport Extreme to clear out the old data it has in memory, with the previous set up otherwise it will not work. Trust me I spent 6 hours trying to make it work reading all Apple Support Community questions and answers relating to this type issue/problem others have been having trying to get their set up working. I tried all the tips, and I finally decided just to see if by chance I would be able to connect with someone with Charter Tech support who might be familiar with Apple to be able to assist me and by luck I did.  He told me why it was not working and was all due the previous configuration with the ATT Uverse router was still in memory with the Airport Extreme. Finally it was 10:30 PM when I decided to call Charter Tech Support and I had been working on this since 3:00 pm pacific. I did not call them earlier as all the post I read said they never received any good help from Charter. After calling them I finished up by 11:00 PM and was able to finally connect Apple Tv, iMac, iPhones and Macbook Pro. We love our Apple Product and Happy all is connected with the new
Internet Provider Charter. I must say the speed is way way much better than it ever was with AT&T Uverse. 
THIS IS WHAT YOU WILL NEED TO DO:
First you will need to unplug the Airport Extreme, then by taking the tip of a pen or paper clip end you need to push the reset button on the back of the Airport Extreme and hold it
down and at the same time plug the power cord back into the Airport Extreme count to 5 or 10 then release the reset button. Then once he light in front of the Airport Extreme stops blinking you need to plug the Ethernet cable from the Airport Extreme to your iMAC or Macbook Pro, and restart which ever one you have, then open the Airport Utility once it is back up.  If you see airport extreme pop up with the old network name or it shows and yellow triangle click on the Airport Extreme ICON it will not let you configure it but will ask if you want to get rid of it or remove and just do it.  Then Again restart your iMAC or MacBook Pro, open up Airport Utility again, and on the top left you should see under “Other Airport Base Stations” the MAC ID for the Airport Extreme.
You will then create/configure a Wireless Network, create your Wireless Password that will be entered on each of your Devices, example, Apple TV, your iPhone, etc., you want to allow access to your Wireless Network you are creating.
Wireless Security will be -> WPA/WPA2 personal or just WPA2
Enter the Wireless Password you want
Verify the Wireless Password (enter it again)
After it is created you will see it on the Airport Utility window with the name you created for it and to the left, will be a Dot (circle that will be yellow).
Next you then want to unplug the power to the Airport Extreme, and then take the end of the Ethernet cable you unplugged from the iMac or Lap top MacBook Pro and connect it to the back of the Modem.
Next unplug the power cord from the modem and wait about 5 minutes, then plug the power back into the Arris Modem and wait until all lights come back on the modem wait
about 5 minutes, then plug the power cord back to the Airport Extreme and you will see it the light blinking yellow.  Wait about 5 to 10 minutes, during this time Restart you IMAC or MacBook Pro, and once it is back up click on the Airport Utility and you should see on the Airport Utility screen.
For INTERNET to the left the light should be green and you should see the Airport Extreme also appear and the light to the left on the screen should also be green.  If they are, you then should be able to click on the Wireless Symbol on top of bar of the screen and click to select the Wireless Network Name you created.
If you Do Not See the light (Icon) next to INTERNET turn Green, or if you see the Internet Light Green, but the Light (Icon) next to the Airport Extreme is yellow, unplug the power again to the modem and unplug the power again to the Airport extreme and wait about 15 minutes or up to 30 minutes. Then plug the power cord back to the modem wait till all the lights light up then, plug the power cord back into the Airport Extreme and Restart your iMAC or MacBook Pro.
The Airport Extreme light should change from yellow to green. Open up the Airport Utility to see what the indicators are showing they should both be green.  Again select Wireless network you created under the Wireless Icon on the top right of the screen. Open Safari and see if you are able to Route to a web page or the apple site should appear.

Answer 1

I just got a Charter Modem. Model TM822. While I was moving, my Airport Extreme was still at my old place.
I have a Linksys WRT320N I used for the initial Charter setup.
I can get my Airport to work here, but the Internet light on the Modem flashes Yellow.
Hasn't caused any issues so far but one thing I did notice.
On the Linksys there were 3 DNS servers listed.
The Airport Extreme only lists 2 and i don't see where I could add another, only change whats already there.
I tried everything above, but light on modem still flashes yellow.
I have the technicians cell phone. Told me "that shouldn't be" and gave the same advice listed above.
I'll break down and call Charter one day, see if it's on their end. NSA tracking may need a reset LMAO.