I have done several R/C to C/L conversions, but not the direction you are going. I made "no Changes." Depending on how old the C/L model (kit or plans?) is, it may be way over designed and hence rather heavy. Also it will not need as big an engine for R/C because it does not have to overcome all the line drag. Some C/L models have different spans on inboard and outboard wings; make them equal. Use normal R/C control surface throws. Many C/L fliers have the CG further forward than a typical trimmed R/C model. Whatever is shown on the plans would probably be OK for initial flights.
Chuck