please take a picture of it from back a couple feet, so we can get a better idea of just what it looks like
is it on all 3 rails & the tailgate?
on your Ram does it have smooth metal on the rail tops? or is it very ugly & uneven on top like the GEN 4, 2009 - 2011 models?
Not knowing more, i would have to say, rip the material off, then take a scraper & whatever else is needed to get the glue off, if the top of the rails are smooth, repaint them where you need to, then get some metal after market rail tops & put them on, OR, get the bed Line-Xed & have them do an OVER THE RAIL spray, it is nice looking & rugged
if the top of the rails are more like the Gen 4 Rams, very unfinished look, i would get the metal rail covers
here is a vendor that has metal bed protectors, as well as other materials, to give you an idea of what is available