I had to replace mine not long ago. I didn't do the work but I think it was fairly straightforward. Basically you drain the coolant, remove the airbox, undo the rear engine and exhaust mounts and jack the engine up 5-6 inches so you can unbolt and remove the pump without the inner arch blocking it. Fitting of new is just the reversal of this. My local independent garage did it for under £200. This guide might help you: https://sites.google.com/site/stoyneff/engine-general/vr6-water-pump-replacement