Before beginning, prepare your workspace to contain the mess and ensure safety. Lay an old towel or rag on the surface beneath your work area to catch falling debris and prevent scratches. Put on your safety glasses to protect your eyes from any small, sharp fragments of hardened putty that may fly off during removal.

Using a plastic putty knife or a similar non-marring plastic scraper, begin chipping away at the exposed plumber's putty. Hold the scraper at a low angle to the porcelain surface and apply firm, steady pressure to get under the edge of the putty. Your goal in this step is to remove the large, brittle chunks that break away easily. Do not force it, as this could cause the scraper to slip and damage the fixture.

For the stubborn putty that remains, apply gentle heat to soften it. Set a hairdryer to its highest heat setting or a heat gun to its lowest. Hold the appliance 3-5 inches away from the putty and move it in a constant back-and-forth or circular motion to distribute the heat evenly. Heat a small section for 30-60 seconds. The putty should become noticeably softer and more pliable. Avoid concentrating heat in one spot for too long, as this could lead to thermal shock and crack the porcelain or melt adjacent plastic components.

Immediately after heating a section, while the putty is still warm and soft, resume scraping with your plastic putty knife. The putty should now peel or scrape away in larger, more pliable pieces. For any remaining thin, stubborn layers, you can cautiously use a metal tool. A flathead screwdriver or a utility knife blade, held nearly parallel to the surface, can be used to gently lift the edge of the putty. Apply minimal pressure to avoid scratching the porcelain. Alternate between heating and scraping until all solid putty is removed.

After all solid putty is gone, an oily residue will remain. To remove this, pour a small amount of a mild solvent, such as isopropyl alcohol or mineral spirits, onto a clean rag. Vigorously rub the entire area where the putty was located. The solvent will dissolve the oily film. You may need to apply more solvent and switch to a clean section of the rag to fully remove the residue. Once clean, use a final, dry rag to wipe the surface completely dry. The area should now be pristine and ready for the application of new plumber's putty or sealant.