Just did mine last week.
1. Disconnect battery. Drain coolant from system. You could place a large pan beneath the lower rad hose. Remove the clamp, pull off the hose and drain the system, hopefully most will end up in the pan.
2. There are four small nuts (10mm) that hold the fan to the water pump hub. They also hold the pulley. Remove fan, leave pulley for now.
3. Loosen off the alternator, pull off the belts. You can leave the power steering pump belt in place, just swing the alt. belt around the steering pump, out of the way. Now remove pulley.
4. Timing cover must come off. 3 - 10mm bolts and one 12mm near the bottom. With the power steering belt still on you can wiggle the cover out.
5. Now you can see the pump. Remove the hose. In no particular order remove the nuts around the pump body. All of them are 10mm.
6. Examine pump. Are the vent holes on the shaft housing stained from coolant? Is there appreciable play in the pump shaft? Have the gaskets, (2 o-rings / 1 paper) failed? In any event, it will be fairly obvious.
7. Clean gasket surfaces.
8. Install new flanged oring in new pump. Install new oring on return line. Hang new gasket on two studs in engine block.
9. All of these gaskets can go on dry. I used a small amount of grease in the return line hole to help the oring slide into place.
10. Installing the pump. First off, get the pump roughly into place and get the return line oring fit into the pump body. Tighten this nut and bolt assembly. If there isn't an Allen bolt fitted here already, do so. It makes tightening / loosening worlds easier.
11. Place the pump flush against the block in position. Two of the holes that fit the studs, as you have noticed are oblong. Put the nuts and washers on loosely.
12. Find a 12-18" pry bar or screw driver. Levering against the bottom most portion of the pump and the crankshaft pulley lever the pump upward. You need to get compression on that flanged oring. You don't have to use terribly much force, but it should be very snug. Tighten the two nuts while holding pressure.
13. Replace the rest of the bolts, on a couple you should use a small amount of thread sealer as they do protrude into the water jacket.
14. NOW IS AN EXCELLENT TIME TO CHANGE YOUR TIMING BELT. (you have to take off the power steering belt if you decide to)
15. The rest is just the reverse of removal.
Also since the system is drained, changing the thermostat (if it's been a while) is good insurance. Inspect the hoses as well, too soft, cracked rubber on the ends, etc...
If you're going to reuse the coolant strain it through a piece of fabric before you put it back (remove the bigger particles.)
Give yourself a solid afternoon, this is an easy job if you're not rushed.
Chad M.