Try a Hair Drier
If you use a regular hair drier, NOT an industrial-strength HEAT GUN, and warm the vinyl, it should soften and then you can get a fingernail under it to peel it off. You may need to use a razor scraper VERY carefully and only at a last resort.Even with a hair drier, don't excessively heat one spot, but move along to warm and soften an area of the vinyl.