Removing numbers & decals
In a previous life, I had the occasion to remove vinyl graphics from a vehicle. My paint guy suggested NAPA Auto Parts. They have a 1/4" drill attachment that looks and smells like a pencil eraser. You cannot use it on high speed equipment like die grinders and the average cordless drill is too slow but the average electric drill works really well. It, in effect, grinds the vinyl into little pieces and turns it into dust. You might want to do it outside because it is pretty messy.
It's not the only way to do it but it worked for me.