I found this on the GE Silicon site: http://www.ge.com/silicones/sealants/diy/ask_ge/faq/troubleshooting/remove.htm#ansHow do I remove silicone sealant?
On smooth surfaces, use a razor blade to remove as much as you can. Then apply mineral spirits to remaining sealant. The mineral spirits will cause the sealant to swell from the surface and become soft, allowing for easier removal. Leave the mineral spirits on over night to really soften the silicone. On vertical surfaces, you may need to continually brush it on. On porous/rough surfaces, removal is more difficult. You may want to use a wire brush in conjunction with mineral spirits.
There is no silicone dissolver we can recommend because silicone is so strong that whatever you used to dissolve the silicone could be harmful to anything else it came in contact with, including skin. There are stronger solvents that can be used to weaken the silicone, but we cannot recommend these products because they may be a danger to the average consumer.