The Hot Wheels emblems aren't removable to be reused. Once their off their pretty much done for. Unless they are the clear stickers like the ones used on the Maistos.
But there is always hope...try using a small scaple and if your able to get the decal off in one piece, try reattaching it with some type of adhesive. I've tried this on one Hot Wheels with limited success...turned out to be butchered job which later went in the trash.
Hopefully you will have better luck than I did. :mrgreen: