1st off if you have a loader the sub frame has to come off and there is 28 bolts holding it on. That is the hardest part of the job. The sub frame is heavy and if can get help do it. I'm 78 and did it myself but it was all I could do.
When I split my 7800 to replace the throw out bearing I went ahead and drilled a 3 1/2" hole over the rear joints. Now I get at both roll pins and can line back up easy when going back on. I wouldn't want to split the tractor at the trans, that looks like a real job.
Here are some pictures of where I put the hole and the cover I made for it. See if that helps. If you do this make sure the pilot drill isn't to long and go slow.