Hi guys I've got a shop window to clean inside and out. On the inside there are several heavy duty stickers. (the clear type with company logo). So what is the best way to remove these as owner has changed and will replace stickers. In the past I've just used my 4" scraper for light stickers/selotape etc. Not tried these yet. Would u recommend any chemicals that will dissolve the plastic/adhesive? I have some Titan Oil-Flow which is good at dissovling adhesive, but havn't really tried it on heavy duty stickers. P.S. These stickers are quite big. The round one is about 2ft round. The rectangle one is about 3ft. Thanks.