Hey Nick. Welcome.
Don't take it apart
right away! Play with it for at least an hour or two before you open it up. In my opinion, the HL PIII is a much overlooked little tank. They're great fun inside the house, and do great outdoors as well. They're lots of fun to upgrade, but my advice is to at least take 'er for a spin before you get to work.
Sounds like you got the IR version?
And it's an unwritten rule that if you tell us you're gettin' a new tank you have to post pics for us, and preferably video. I've seen video of a zillion HL PIIIs and I can't wait to see a zillion more.