I trust you blocked your wheels and pulled the emergency brake.
Don't laugh, I have a driveway with a slight slant and was about to pull the shaft on my previous motorhome, when something dawned on me......
The cups are removed with a vise using 2 different size sockets. One small that slides into the yoke and the big one for the cup to slide in on the other side.
The two driveshafts should just pull apart at the center support bearing. Look for the alignment key when reassembling.
The driveshaft should have been marked in relation to the transmission and rear gear flanges before disassembling.