I've read it's a bitch to get the back off, and the speaker gets pretty attached inside. I have 2, and want to experiment with one.. Thought of a V30, or maybe a Mesa MC90 if I can get one 16ohms.
If you pull the jack plate you should be able to use that access hole to pull it out. My Schecter USA 4x12 is tight like that and I have to remove the jack plate every time I swap speakers to get the back off. That is a sign of a properly made air tight cab.
I have two Friedman 1x12's. I put V30's in both of them.
The back IS on super tight. Removing the speaker jack and pulling on that little hole is futile. It won't work.
Remove all the back panel attachment screws. Then you'll have to give it a good whack on a carpeted floor at an angle, so one of the corners on the backside hits the ground. That'll knock the panel loose. Otherwise it's not coming off. Sometimes it takes a couple tries.
Getting the actual speakers out was not any more difficult that any other cab.
I've done this numerous times with no damage. Just use common sense and don't drop it from 6 feet of the ground.