Want to Use eHD for Primary Storage

Question

Good day,
My question basically is: How do I change over to use my eHD as my primary storage instead of using it for back up through Time Machine? AND Can anyone explain how to do it as though I just plugged in a Mac for the first time yesterday?
Background: About 2 years ago with some great advice from people who answered a previous post I purchased a 1TM OWC external HD.  I was down to 4GB left available on my internal and I find myself in a similar situation now with only 11.93GB left on my internal HD despite the 1TM eHD which is only a fraction full. 
2 years ago when I originally connected my eHD I was given the option to store directly to eHD OR use it for back up through TM.  Being a novice to it all and for whatever reason, not sure why exactly but at the time I chose to back up through TM.  I was having issues with getting TimeVault turned off and was overwhelmed etc. etc. 
Anyhow--flash forward 2 years later I am filling up my internal again with only the 11.93GB left that I mentioned.  According to OmniDiskSweeper a good 142.9GB of it is coming from my movies---mostly the events vs. projects of course but 142.9GB none-the-less.  I know when I import movies from my camera I can choose to direct them to the OWC but because the internal shows up first by default, sometimes I rush import without changing it to the OWC, hence filling up my internal.
Basically what I really want to do is  store everything directly to the eHD and I am not sure how to do it.  Is there anyone that can walk me through the process in simple, simple terms?  Although I feel I've come a long way in 2 years I still consider myself a novice. 
Yes, I have read many posts, threads, discussions but with different suggestions so not sure what is right.  I am not familiar with this stuff such so I end up being afraid to "try" any of it for fear of losing my pics, movies forever. Or having to re-do them somehow.  I read about just moving iMovie but too many options as to how and not sure which is right.  Most forums are for people who know more than I about this already and suggest things like change events to view by volume (did it) but then I read stuff like open volume where events are stored and drag to volume you want to store it.  Well for someone like me that raises more questions than answers.  What volume?  Do they mean in my case drag to the eHD?  Will this keep everything the same as I had it?  Will I still have my dates?  Titles?  Some discussions say copy.  Do they mean move?  Etc. Etc. Etc.
Really I want to just store directly to eHD for primary.  I want to be able to open iMovie, iPhoto and have everything just like I do now but with all that glorius 1TB storage.  I don't want to redo anything---just move and run off the eHD.  Possible?  If I simply unplug my eHD and reconnect---will I get the option I did 2 years ago to store directly to the eHD?  
UGH! 
Message was edited by: dgc0225 to re-arrange wording just after posting

Answer 1

Hi BDAqua,
If it's "easy" I would consider getting another 1 to 2 GB. 
I read a post before I posted here that referred me to Ken Stone's site about formatting and partitioning but I couldn't change the "Volume Scheme" like in his examples.  My real ones were greyed out so I didn't have the option to select.  And honestly--reading on it's pretty complicated (based on my lack of knowledge with this) and I'm afraid I would screw it up anyhow.  Anything else besides partitioning? 
Anyone know what happens if I just turn-off Time Machine? What if I unplug the eHD and plug back in and start over?  Like a re-boot of sorts?  Too good to be true?