How to sell a used 5th wheel

Craigslist. Follow it and rvtrader for awhile to get an idea of fair value, and then knock a bit off for a quick sale. I've sold both trailers and vehicles that way and a quick sale is worth it versus making a little more but having it listed and showing it for multiple weeks. Craigslist dominates classifieds in my area but you might need to try whatever equivalent you've got in your area if it isn't CL.