A razor blade scraper works well, but you have to be very careful with it so you don't gouge the finish. I removed all the old worn out loopy graphics using a heat gun, Googone, and the razor scraper, I cleaned it up when it was all done, with simple green to get the Googone off, then rinsed it. At some point I need to apply a cleaner and wax, but I have to go camping first. The snow in the Sierra is beginning to melt and the campgrounds are starting to open.
Wit the sticker over the graphic, that is going to be tough. If you can heat up the warning sticker glue enough without heating up the graphic glue, then you should be able to do it. Since it is new, the glue hasn't had a chance to cook in the sun for years, like mine did, and it may peel back ok. If the graphic sticker comes up a little, a plastic squeegee can smooth it back down provided the glue doesn't get guck in it.
As for the effectiveness of warning labels, I vaguely remember in the days I defended law suits, including warning label cases, that there was an industrial safety study that suggested that there was an inverse relationship between the effectiveness of warning labels and the number of them. One of my favorites is the label on the Superman costume's cape that advises the user that one cannot fly using the cape. And this was on an adult sized costume. I think the gene pool might be better off if .......