Lay plastic sheeting on the floor below the door to protect it from the cleaning agent.
Moisten a soft toothbrush with paint stripper. Scrub the stripper onto the paint spots.
Wait 15 minutes for the stripper to soften the paint. Scrub the paint again with the toothbrush to remove it. If the paint spots are stubborn, scrub gently with a fine steel wool pad.
Soak a paper towel with paint stripper if any of the paint remains. Lay the paper towel over the paint spot and leave it there for 15 minutes. Scrub with the toothbrush until the paint is gone.
Wipe the brass with a damp rag to remove any residue. Dry with a clean, soft rag.