https://www.youtube.com/embed/RaeVHlQb1R4?version=3&rel=1&fs=1&autohide=2&showsearch=0&showinfo=1&iv_load_policy=1&wmode=transparent 

Demonstration of removing graffiti from a vinyl film laminated with Concept 108 Tedlar Anti-Graffiti film. Graffiti sample had been on the film for about 2 weeks, and is removed with the proper solvent. I try three solvents as a test.

via Graffiti Test (video) — Southern California Custom Sign Shop - Big City Signs