As above – it will be possible to disassemble further….. unless the laws of physics have been overcome?
If you really have to keep it assembled then it’s blind bearing puller time but they aren’t capable of much pull so you’re going to need lots of co-effecient of expansion (lots of heat into the casing).
Worst case scenario is a 9″ grinder cutting through the thin outer section of the casting and then the outer and inner bearing races. You’ll then need a reinforcing section designing/Lasered/machining that picks up on those two bolt holes to reinforce the split in casting you’ve just cut through. It would make bearing changes quicker next time.
Or cut the whole thing off and CAD / laser a plate that bolts to the casting on the area that is out of photo, pick up on the centre line of the shaft but use a flanged bearing instead.
However the easiest thing is to Capex a new pump and bollock who ever made you use an obsolete knackered bit of kit.
* I have Solidworks, a massive manual turret mill and lathe, 24hour turnaround laser and machining contractors at my disposal for this sort of thing. I also have an expensive SKF hydraulic bearing puller kit which is handy for stuff like this.