I've never met a water pump pulley that a couple sharp raps from a hammer wouldn't loosen but usually a medium prybar will get them loose. If you go for the hammer, use the lightest one you have. You don't want to move metal, just break the bond.

At this point you may have to replace the pump, just for your own piece of mind. You can check to see if you have a metal pipe that comes off of the back of the water pump and disappears under the intake. If so, its going to the oil cooler.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff