A sharp single edge razor blade is an excellent way to remove stickers from windows. You lay the razor's sharp edge flat against the window and slide it under the sticker. Use windex as you scrape to provide lubrication and minimize scratching on the glass.

As far as the one on the paint, that will be more difficult. You can try a blow dryer to melt the glue on the back of the sticker, but chances are that it has been there so long that the glue is dehydrated and solid, so the heat wouldn't work. In that case, it will be a piece by piece effort. Do not use the razor blade as you will remove the paint. You can try gunk remover (try "Goof-off") to remove the residual adhesive, but be careful to test it on an inconspicuous place on the paint first to make sure it does not cause damage.