William,

I've never had to replace a water pump in a Diamante, but I hear they can be quite difficult. My suggestion would be to go to AutoZone, PepBoys, or other auto part supply store and buy a repair manual for your car. They cost around $14. If I were to try to walk you through it, I'd be afraid of screwing something up. There are a LOT of steps involved in that procedure. If you have any doubt about your abilities to change the pump, take your car to a qualified mechanic.

If you do decide to change the pump yourself, this would be a good time to replace all the belts (excluding the timing belt.) This includes A/C, power sterring, and the water pump belt.

Sorry I couldn't be more help. Good Luck!

Anthony