Bill Ball

Usually it is corrosion that cements the balancer on. Use some emery cloth and make sure the crank and balancer mating surfaces are very clean. You should not need to heat it.

Now, on to the WP - the major hazard there is snapped bolts. The pump is held on by a bunch of rather delicate M6 bolts and even though they do not enter the water jacket, they do get corroded enough so that snapped bolts are common. The bolts should give up their tension with a decided release. If any seem to not release cleanly as you turn them but continue to turn with resistance, you are probably twisting the bolt and it will snap if you continue. Penetrant, heat and a few wacks to the bolt head with a hammer to break up corrosion are recommended. Unless the WP was done recently and new bolts with copper antiseize were installed, breakage is almost inevitable.

AO

I highly recommend using anti-sieze during reassembly. The PO or PM on my car used it and it came right off. I use that stuff all the time now. AWESOME stuff, I tell you.