Apply WrapCut on the area With all the filament (tape edge) positioned on the desired trim line. Leave about 4 inches of tape uncovered outside of the edge with the film so which the reducing filament might be located. Push both the movie and tape down firmly towards the area. https://www.apptape.co.uk/blog/5-key-benefits-of-using-wrapcut-filament-cutting-tape-in-your-vehicle-wrapping-projects/