Sweep to remove any loose dirt and debris.
Divide the floor into 4-foot by 4-foot sections — the measurements don't have to be exact. Mark the borders of the sections with a black marker.
Apply a thick coat of polyurethane stripper to a corner section of the floor with a large paintbrush. Allow the stripper to sit for 45 minutes.
Scrape the treated area, starting from one edge. If the paper has not softened, allow the stripper sit for another hour. Once the paper is scraped away, apply stripper to the next section.
Rinse the scraped floor with a wet mop and allow it to dry overnight.
Sand the floor with a belt sander to remove any remaining paper and glue residue.