I just had mine replaced on an 07 RR S/C. They have to remove the door panels to switch the door handles. The handle kits are $24 at the dealer. They will charge a $100 labor per door to change it for you. I was thinking of doing it myself but did not want to mess with the the clips on the door frame. They are a pain if they are broken. I was lucky that my service advisor was able to put it under warranty. You might want to buy the handles and have an independant shop do it for you and save some money.
Same problem here on my 2003. I went to a local auto body shop and was told it would cost $100 per handle to repaint . I decided it would be best to buy all new handles and replace. You can get 4 new handles from rover connection for about $200 and easily do the install yourself if you take your time. Although I have not done the door panel removal on the RR yet I have done it on several other cars to know it is fairly simple if you use a good door panel removing tool - like a soft cat claw -and you take care to not overly pry the panels out that may damage the clips or the panel itself. The learning curve is quick - once you do one door the next three go much faster - the key here is patience and a soft touch.
1) Disconnect battery
2) Remove panel screws (hiding under trim)
3) Remove panel - unplug electrics
4) Remove vapor barrier, or peel back to expose inside handle
5) Remove and replace handles
Don't forget to disconnect the battery (and wait 5 minutes) before taking off the door panels and disconnecting the air bag sensors - if the battery is connected you will throw a code that can only be extinguished by the dealer. I will try to find a listing of the door clip placement and screws/bolts that hide under cover panels, or I will take some pics when swap out my handles sometime this next month. Once you know the location of all the hidden screws and clips it is a fairly easy but time consuming process.
They are a little bit more difficult than I thought. Once you do one door the rest become easy and faster. The first door took me about 2 hrs to complete. Taking off the door panel is the easiest part. They use the highest quality clips I have seen they are hard to break.
As promised, the RAVE instructions for door panel removal. For those of you who wish to replace the handles and/or window switch plates I have attached a .pdf of the RAVE for both front and rear door panel (trim casing) removal.