Is it the remote control motors or the actual mirrors that have failed? Any good glass installer can cut and make new mirrors. The rest is more difficult. If you are needing to replace the whole arm and head, I suggest you start by checking for access to the back side of the mounting arm. It might be easy or very difficult to get to the bolts holding arm to the side of the RV.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI