being a fresh decal it should pull right off, you shouldn't need anything special. If anything some googone to remove any adhesive, but should be fine without anything since it was just installed.
I wouldn't ask them to remove it, I'd ask them to walk around the truck with you to check for any damage, etc. when you accept it. And when you get to the tailgate I'd go "what is this?" and immediately start peeling it off, and hand it over to the salesman and say "i think this belongs to you" lol
Did something similar with our 5.0. It was drop shipped to a dealership, and it was there ALLLLLL friggin day, and we told them the day before we'd be there to grab the car as soon as it arrived. Well all day goes by, couldn't get ahold of the sales rep, left messages we'd be there at 2. Called before we left and finally got ahold of him and said we'd be there in about 90 mins, have the car ready. Got there and they hadn't touched it. Give a big speal about they won't be ready for hours, blah blah blah. I said do the bare minimum you need to do, I'll clean the car myself, just do the required minimum don't bother cleaning it. Well they took about an hour, brought the car around front, and it was filthy dirty as expected, BUT, a plate frame for their dealership and a decal on the trunk lid for their dealership was slapped on the car. WTF!? Since the car was parked in front of the big glass window where the sales rep sat, before we pulled off I jumped out and peeled the sticker off right where they could watch lol.
