scrape off
To remove something (from some surface) with or as with the vigorous scrubbing of a rough, sharp, or hard-edged instrument. A noun or pronoun can be used between "scrape" and "off." He used a putty knife to scrape off the old paint from the wall. Stop scraping your scabs off or you'll end up with a scar! I had to use my fingers to scrape the mud off my windshield.
scrape something off (of) someone or something
and scrape something offto rub or stroke something off someone or something. (Of is usually retained before pronouns.) I sat down and scraped the caked mud off of me. It was everywhere! Jake scraped off the rust.