The 'normal' technique is to remove the attached thermostat, then with this out the way you can slide the waterpump out. My issues started with snapped bolt heads holding the thermostat to the pump housing. Now everything would have to come out a single unit to be split on the bench. To do this the metal water pipe running from the thermostat housing behind the water pump and crankshaft pulleys to the RH head has to be removed. If the hex socket bolts holding the pipe to the head shear off you are in a potential world of pain removing the remaining stud. If you cut the pipe just to the left of the distributor shaft (see arrow in the photo) then this is the one spot you have sufficient clearance behind the pulleys to fit a piece of hose & clips to rejoin after your pump replacement. This technique will avoid having to remove the two hex headed bolts should they not want to come out cleanly.
Of course you may not discover that the bolts don't want to come out too late for this to be useful (as I did , so then you can practice the technique of welding a nut on for stud removal which worked a treat)
Removing the seized bolts from the Thermostat housing is another story .. that involved drilling out and refacing the housing.
