1st of all you could do with a nice hot sunny day so you can have the sun on the van for an hour or so then with or without the help of a window cleaners/car valeters safety scraper or just your nails start in the top corner of the sign writing closest the sun surprisingly it does make a difference start to peel away at the corner and depending on the vinyl it should start to peel of pretty easy the hotter the van/sign-writing is the easier it is that's why most people use a heat gun for any sticky bits left which there will be even after using a heat gun clean off with brake cleaner or tar and glue remover spray/wipe on wipe off