Can't comment for other members or for your specific X5 model but I did remove the radiator and it gave me a lot of room and facilitated the WP replacement.

I was able to do it with the car on ramps and without having to remove wheels despite posts that indicated that was a requirement.

I have some links that I used as well....not X5 though

Pictures: Electric water pump + thermostat replace

this post was the best, specially as I ended up replacing a few hoses as well....(I hope is ok to post these here...)

DIY - E60/N52 Cooling system overhaul - Bimmerfest - BMW Forums