NP-1 caulk is a polyurethane sealant used mainly for exterior home improvement projects, such as those involving roofs, storm windows and exterior doors. The caulk is easy to load in a caulking gun, bonds easily to most surfaces, works well with many types of paint and is weather resistant. When it comes time to remove and replace the caulk after many years, NP-1 caulk is no more difficult to remove than other types and brands of construction caulking materials.
Run a putty knife along the right and left seams of the bead of caulk to loosen the caulk from the surface.
Slide the edge of the putty knife under the bead of loosened caulking material, and lift it up from the surface, sliding and lifting as far along as you can until the seam of caulk breaks.
Lift the loosened caulk off the surface with your fingers, and pull it the rest of the way off.
Repeat steps 1 to 3 until you have removed all the caulk. Throw away the old caulk.