Can it be easily screwed back on? If the trim is not damaged I think I would just put it back on. If it's damaged, I'd first call my dealer and explain the situation, and assuming it can be re-installed easily, see if they can order a new piece of trim and ship it to you.
Heartland Big Country 3150RL
2013 Ford SD F250 4x4 SC; 6.2
Reese 18K Elite w/slider - Rockford, Michigan