The oil pump on these cars is much easier to do than most other cars. You don't even have to remove the oil pan. In the fron of the motor where the oil filter screws on, it is screwing directly on to the oil pump. It's external. All you have to do is remove the oil filter (food time to change the oil) and remove some 10mm bolts (about five or six). Get an oil pump rebuild kit (don't go high volume unless you want to remove the timing cover too). You replace the two gears and the pressure relief spring. That's about it. You must be very careful not to nick the aluminum housing when scraping the old gasket off. When you install the new gears, pack them will with Vaseline so the oil pump will prime (start). Before you go buying that car though, make sure the motor soen't have a spun bearing though. It's real easy to say you have a bad oil pump instead of a bad motor. A spu bearing will also cause your oil pressure to drop to almost nothing. I say have the current owner replace the oil pump and if it's OK after that, go ahead and buy it. This is just to cover your end so you don't get stuck with a car that has a bad motor.
