Tailgate Insert Delete - Adhesive from Hell

Just be careful with these. They certainly work, but they'll work right through the clear coat and paint if you let them. I used to do signage and vehicle wraps / graphics professionally... seen some newbies destroy paint before when they don't know what they're doing with the eraser wheel. Eraser wheel also isn't necessarily ideal for recessed areas like this.

OP: the 3M wheel is different than the remover people are recommending ... I'd personally start with the 3M adhesive remover like others have recommended. Be patient with it. Get a bunch of those blue shop towels and some plastic razor blades / scrapers. The adhesive remover will cause the adhesive to ball up into mucus-like chunks which you'll scrape up and remove with the blue shop towels. More isn't always better, especially once you have all the big stuff up. Too much spray will mask thinner layers of adhesive and you'll think you're done even though you're not. Keep at it and be patient. Removing the tailgate and throwing it on some sawhorses or something might be a good idea for the sake of your back.

 

The spray is what I have used in the past, but it had already been suggested. Then again, I had never had that much adhesive leftover.
Good to know the potential cons.