Crawl under the trailer with a pressure washer, safety glasses and and old clothes . do the whole unit under all the frame and where ever you can reach. Then Putty knives and screw driver, scrape off all loose stuff. Then get 5 cans of rust spray coat, FACE MASK and glasses. spray every where you can.
Let dry, then go back and re-scrape the rest of the loose spots. Then re-spray . Now get some good rust preventive top coat paint and re-paint the under side again.
I have done this, it is quite tedious but well worth the time and effort.
The jacks you might just wish to replace them. but what ever you wish, the hitch, take it down to a sand blaster and have them do it up good , you can re=paint it .
Have fun and relax. This will be a couple of days project.
Chuck
