RV Repair: wood rot, wood rot, dining area

Question
I have a 2003 37DD Hornet travel trailer with  wood rot over the big slide in the living/dining area. Not covered by my insurance. How hard and how expensive is this going to be to repair?  Caused by the run off from the A/C. And what can we do to prevent the run off from getting on the slide? We set up where it runs to one side to one end, just by setting it up just a little off, (not level). Apparently this was done before we bought it.  Thank you  

Answer
Better have a professional do it. It might be expensive, but in the long run it will save you from future problems, if done right the first time.
It's tough for me to tell how much is involved without seeing it.
Get several estimates. Often, smaller repair shops are less expensive than the large dealers, and I have found that they usually do a better job.
Dave