Just buy some 3M Silicone Caulk Remover. I've never used any, but my impression is that it swells and softens the caulk, which causes it to lose its adhesion, making it easy to remove.
Used this stuff to remove silocone from my aluminum portlights and the glass. Made a mess but the silicon sludge came off with their specially formulated wipes. This stuff is industrial strength so be careful. Also worked great removing excess Silicon I had applied to seal my Lexan MR10 portlights as I wasn't the best/neatest with the caulking gun. I just brushed this stuff on to the cured silicon and let er eat for a few hours. Kept it wet with the Digesil as instructed.