"IF" one can do as Tom mentioned, a 5/16 allen wrench or equal to remove the screws, turn the head 90* is the fix. This is the BEST and simplest option.
For those that can not do this......Then the only options are to extend the draw bar, or lengthen the hitch itself. Both have plus and minus's. What is a plus for me, may be a minus for you! or vice a versa.
Some of the things I like about lengthening the hitch.......
I can many times now jack knife the trailer with out hitting or denting the truck with trailer at 90+ degrees. ok, maybe 92-93 degrees depending upon hitch length......Depending upon how done, you can put additional batteries etc up front.....
BAD! adding batteries or equal to the hitch as many of us know, you add hitch weight, which could overload your current receiver! so you may need a new receiver. OR to counter this, add some items to the back/behind the axels of the trailer. Even just extending the hitch could add some wt to the hitch head, not that it will, but if you are close to the receiver hitch rating, you could go over.
Another thing about hitches to think about. Per the body builder of the hitch and bed for my dump truck. A typical 5/8" pin for a hitch, is really only good to 10K lbs of trailer capacity, be it WD or DW hitched. How many of you, myself with the 2.5" hitch on my old 05 dually, had a 5/8" pin in a hitch rated to 15K lbs? He mentioned needing a 3/4 or 1" pin! I asked this, as I pull a 12.5 lb pintle hitch with this truck. The rest of the hitch is good, but the weak link was/is the pin!
Marty