try using your nail, thats what i did
To the OP, if the lead stays on the frame for too long, it will not be easy to remove. It will break easily when trying to remove and will be pain.
I use a plastic or wooden knife and slowly try to peel off enough so that I can grip it with my fingers and patiently take it all off...
i used a razor blade. but i did it carefully. no scratches from the razor blade on the frame, but some of the paint did peel off if i went too fast (figures)