I just watched this video about winterizing an RV.  While a Roadtrek is the vehicle in this video, the process applies to all RV's including FMC's.  I am in CA in an area where we do not have to winterize but should things change, I might need do this.

Also, I have heard of others having to repair freeze damage to their coaches due to inadequate winterization.  This video was produced by FMCA and it does a very good job of explaining not just what to do, but why.

http://www.youtube.com/user/fmcaonline 

See you at the next rally,