F4580 won't connect to new O2 wireless router - still showing as connected to old one

Question

Wireless light constantly flashes.
It's still connected to the old router even tho that is disconnected but it is recognising & discovering the new router.....
Results of NC page as follows:
802.11 Wireless
Hardware Address (MAC) is showing
Status             Disconnected
Connected PC(s)
no IP Address - printer is wired up to a MAC (the HP software is installed on it too) & it prints from that fine but we also use it to print wirelessly from a WIndows 7 Laptop & other Apple handheld devices
Number of 802.11 networks discovered: 1
SSID is new router name
Privacy RSN    Auth  WPA-PSK    Encrypt AES/TKIP    Signal -63    WPS Yes
Diagnositcs Summary
Wireless On                                     PASS
Wireless Networking                      PASS
Network Name (SSID) found        FAIL
Security                                            PASS
Printer Settings Consitent with Wiresless Router Settings     Not Run
No Filtering                                     Not Run
Connected                                      Not Run
Signal Strength                             Not Run
Other Networks Detected            Not Run
Wireless Networks Detected      2
Downlink Counter                        155
Channel                                         Not Run
Configuration Summary
Network Name (SSID)                      showing old router name
Hardware Address (MAC)               showing an address
IP Address                                          Not applicable
Configuration Source                       Not applicable
Communication Mode                     Infrastructure
Authentication Type                        Open System
Encryption                                         64-bit WEP
Any help would be greatly appreciated :-)

Answer 1

Thanks for your response Dean!  There is no 'screen' on our printer so I'm a bit perplexed how to do what you have suggested.  On top of the printer, left hand side there are button's for:
Power
Cancel
Scan {USB only}
Copy Settings x 2 buttons
Black
Colour
Wireless
Basically all we need to know is how to reconnect the Wireless to the new router.  The HP Software is working fine with the Ethernet connected MAC & we have no problems printing directly from that.  Once the printer is connected to the new router the other devices will be able to see it & connect.
Thanks!