Most Rv dealers have conversion kits in stock for the Coleman a/c your asking about. I'd try there first. Since it involves modifying expensive circuitry, I'd have a Coleman dealer perform the modification.
The conversion of a remote controlled Coleman A/C unit on a RV to a wall mount thermostat depends on the model of the A/C unit. However, the basic instruction involves checking the electric circuit and the wiring of the A/C unit. Ensure that the 2-amp fuse is open. Go to http://www.cleggind.com/postal_tech/pdfs/AC2/airxcel_1976376%5B1%5D.pdf for detailed info.