How do you remove melted plastic from material?
One time I used a sheet of paper and an iron. Lay the sheet of paper over it and take a hot iron and put over the paper. It will melt the plastic and it will stick to the paper. I am not sure about melted plastic, but I've removed dried wax from fabric by placing a brown paper bag (usually a lunch bag) on top of the wax (or plastic in your case) and running a medium heat iron over the bag. The wax came off, so maybe it will work for melted plastic.