I took my pump into the local guy last year with new bearings, seals, impleller, etc. He said "just buy a new pump" So, I figured why not destroy this one if I am going to have buy another one!?!
To answer your question, yes the shaft is pressed in. I had a problem when I pressed mine out, half the bearing stuck to the shaft. I ended up needing to get a bearing puller to get it off. I ended up getting the whole thing rebuilt and mounted, but it had an ugly wobble to it, so I ended up just buying a new one for $130.