As said before,acetone will soften it up so you can wipe or scrape it off with a wooden stick. If you've no acetone around, try soaking it in your wife's/girlfriend's nail polish remover. Most of those are mostly acetone.
DO NOT get acetone on any plastic parts. While it may not totally destroy the polymer which usually holds G-10 and carbon fiber together, it's not worth the risk. Also, acetone is an excellent de-greaser, so re-lube the knife ( if it's a folder) after you're done.