Take what I am abotu to say with a grain of salt - this is basedon experience removing a water pump - but have not done so in my XJ yet.
Step 1: Visually locate all components that will need to be addresed - Water pump, Water pump pulley, idler pulley, radiator, coolant temp. sensor, etc.
Step 2: Spray penetrating oil on all relevant bolts and fasteners. This includes silly things like hose clamps.
Step 3. PLace place bucket under radiator drain hole. Remain Calm
Step 4. Remove drain plug. if unsure of condition of drain plug, you may choose to remove lower radiator hose. Come to think of it, why not replace your hoses now?
Step 5. Drain radiator. Remain Calm
Step 6. Repeat Step 1
Step 7. Remove bucket of coolant from under car. Empty bucket into appropriate container. Use a funnell.
Step 8. Detach Coolant hoses and temperature sensor from the water pump housing. Remain Calm
Step 9. Loosen Idler pulley main bolt. (15mm) This may/will be difficult. Will most likely require the use of a box wrench slipped over the end of the bolt, parralel with the ground. Use a short length of pipe or similar braced against the other end, and tap it with a mallet to loosen. Remain Calm.
Step 10. Loosen tensioning bolt (15mm) located to the upper left of the pulley, next to power steering pump. Remain Calm. It may be necessary to tap the bolt backl down against the bracket as it comes loose to move the pulley. USe the pipe and a mallet to tap it gently down.
Step 11. Repeat Step 1
Step 12. Memorize, jot, or take a picture of the belt routing.
Step 13. Slip belt off of water pump pulley. Why not change your belt?
Step 14. Loosen the bolts of the WP Pulley and remove. The use of two wrenches will be necessary to get the bolts to turn without spinnign the pulley. Remain calm. (Editors note: hey? can we loosen them with the belt on to make this step easier. . . is there a reason why not?)
Step 15. Remove bolts holding water pump to engine.
Step 15. Remove water pump. Hold it over your head in victory.
Step 16. Put the water pump down. Stop dancing.
Step 17. PLace clean rag in hole to prevent crud from falling in your engine.
Step 18. Carefully clean old gasket from engine block.
Step 19. Remove the rag.
Step 20. Apply gasket sealant to new water pump and engine block <- not sure about this
Step 21. PLace new water pump in position. slide bolts in to hold it in place. Remain Calm
Step 22. Tighten bolts to correct torque specifications < - Can anyoen help him out wiht this?
Step 22. Reinstall water pump pulley. Remain Calm.
Step 23. Replace Belt on water pump pulley - if new one, make sure to route correctly. loosen the idler pulley further as needed.
Step 24. Check routing of belt.
Step 25. Replace All disconnected hoses and temperature sensor. Are they new hoses? Did you get new clamps?
Step 26. Retighten tensioning bolt. Remain Calm
Step 27. Check belt tension.
Step 28. Tighten main idler pulley bolt.
Step 29. Check belt tension.
Step 30. Did you reattach ALL the hoses? What about the lower one? Did you take that off to drain and then forget about it since you;ve been working up top?
Step 31. Reattach lower radiator hose. Remain Calm
Step 32. Refill coolant system.
Step 33. Call friends for ride to Autozone to purchase coolant. Remain Calm
Step 34. Refill coolant system.
Step. 35. Start vehicle.
Step 36. Check for leaks.
Step 37. Drink.