Power steering pump rebuild / reservoir removal

[nyncompute]

I want to rebuild my power steering pump and thus retain the original canister with its original look and hose orientation. Problem is the dang thing will not release from the body. I tried to gently massage it off with a rubber hammer but no go. Also tried a bit of heat...nada.
If I get to aggressive it will start to dent as it has fairly thin metal. Any tips?
Oh and yes the bolts are all off