I did mine. Pretty simple, just have to take your time. The trans can stay attached. It's a 2 piece seal. Just gotta get the oil pan off, and then the last bearing cap off at the rear of the block. The other part if the seal is still in the block on and will probably need pushed out with a pick. Then should be able to pull out the when its sticky out far enough. Installation is the same but I the seal that goes into the block had to face a specific way. I forget his it goes but just live it up and be careful not to rip it. Otherwise you will have it all buttoned up and the seal will leak again. If you have the cash you should replace the oil pump too just to make sure that's all good. I didn't and now a year later I gotta change it now.
I thought my rear main was leaking but when I pulled the oil pan to change it I found the rear main to be fine and it was just the back part of the pan gasket. If you do it yourself do not skimp on a new pan gasket. I bought the felpro molded one piece gasket and I haven't had a drip since. Definitely worth the extra couple bucks. Do the oil pump while your in there, you won't regret it. There's also a metal strap that tightens the curved back part of the pan with two bolts. Mine was stretched so I fixed it by closing the little tabs on it with a punch in my vise. Might want to look into getting a new one if possible.