Jeff is right. This is a major nightmare to replace. The roller pin is the difficult part as you have to relieve the pressure from the cable so there's enough slack and then snap the roller pin into the 2 "C" holders on the bottom of the plastic handle. Our driver's door handle had the roller pin snap out of the "C" holder as one of the holders broke. Of course, this happened the day before we were to depart for the Giro Roadster Running of the Bulls, which was a Sunday. Luckily we were rescued with a brand new part as we were to pick up Valentino Balboni from LAX on Monday, the first day of the event. We called him and told him the situation and sure enough he showed up and pulled a brand new handle out of his luggage. He saved the day! Anyway, the door got fixed but it was a chore and we only did it by trial and error. I say we because Mrs. LOUD V12 helped me and believe me if you're going to attempt it yourself, you need another pair of patient hands.
My advice? Take it in to an authorized dealer and have them do it.