Theoretically possible, practically, just too hard. The first time I tried it in 1973, I ended up pulling the engine and trans anyway. It is just easier to drop the engine & transmission out the bottom (do NOT follow the shop manual and try taking it out through the top; again, theoretically possible, but way too hard and requires a sturdy and adroit assistant), do your business and put it back in. I have, by myself, pulled e&t, replaced a failed throw out bearing, reassembled the two and put it back in the car ready to run in time for dinner the same day. That was, however, 40+ years ago. You will need a rental engine hoist to pick the car up, a couple short pieces of 1/2” chain and at least a nice sturdy creeper to drop the engine onto and roll around. I don’t use a creeper (but others have successfully), I have built some rolling engine dollies out of scrap angle (discarded bed frames work great and can frequently be found for free around the neighborhood or really cheap at garage sales), you’ll need about 15’. You’ll need to buy four 2 1/2” steel casters and weld them on the corners. If you need more detail, email me and I will send you some pics of a couple of mine. Good to store spare engines like your high mile 260 when you swap in the 5.0l rollercam replacement.