Sweep the floor thoroughly, removing all debris, dirt and dust.
Mask around the walls with painter's tape and kraft paper. The stripping and cleaning process may damage unprotected baseboards and paint.
Spread a citrus degreaser over 4-foot sections of the concrete floor. Sweep it in an even coat over the concrete and allow to soak in for 30 to 45 minutes. If the degreaser is drying too quickly, lay wet bed sheets over the solution.
Scrape the degreaser sludge off the floor. Pull the bed sheets off the floor and place in a container for disposal.
Spread water over the floor with a string mop. Run a floor polisher with a scrubber pad over the concrete to remove the remaining sealant.
Vacuum the degreaser and water solution off the floor with a wet/dry shop vacuum. Dispose of the sludge by placing in the container with the bed sheets.
Mop the floor with clean water. Allow to dry completely before resealing or staining the concrete.
Clean up with soap and warm water. Rinse the shop vacuum and mop thoroughly.