silverskin?
Are you talking about the silver skin, very tough fiber sheet that can be found outsdie of many muscle groups? If so, the best way is with a nice darn sharp fillet knife for me. Just slide the knife under the silver skin, angle it toward to the silverskin like you were taking the skin off a fish (assuming you clean fish) and slide the knife along peeling it off. You will have to do it in strips but with practice it comes off pretty quick.
I normally butcher deer the day or next day from when I kill them, it comes off fine.