Alot of times it takes a slide hammer to get the pump to pop off. I've never looked a 5r, but most automatics have threaded holes in the pump just for this purpose.
thread bolts into the pump use some big washers so you can pull on them and the pump should come out. dont forget about the thrust washer on back of pump. put some grease on it to hold onto new pump. if the thrust stays in the case just use a magnet to get it out. Its way easier that trying to line it up with the thrust washer on the new pump. Its been a few months but off the top of my head thats what i recall.
I used a two bell housing bolts, threaded them in a bit, used a 13/16 wrench to pry against the casing and pry under the bolts and it popped out pretty easy. getting it to line up again is tough
As said above but mak sure you find the 2 bolt holes on the pump that are threaded. Chain and slide hammer or pry bar with some blocks of wood worked great