If you're trying to remove hardened glue residue, there are a few different methods you can try. One is to use a putty knife or a razor blade to scrape off the residue. You can also try using heat to soften the glue, which will make it easier to remove. Another option is to use a solvent like acetone or nail polish remover. Be sure to test the solvent on a small area first to make sure it won't damage the surface you're trying to clean.