I have had the occasion to replace several door handles on 700/900 series vehicles. The tricky part is getting the nut off inside the door while the bolt is spinning in the plastic housing. After trying several different methods, I hit on one that works very well. After removing the outer handle cover,I heat (with a torch) a cheap 1/4 in. drive 10mm socket to the point it will melt into the plastic, and onto the bolt head, the rest of the job is just remove and replace.
Poorgie