Remove Old Drain Flange & Clean Opening

What happens here

Use a specialized pliers wrench (like the Knipex Cobra shown) to unscrew the large nut securing the drain flange to the bottom of the sink. Once the nut is removed, use a utility knife or scraper to carefully remove any old sealant, caulk, or mineral deposits that have built up around the drain opening on the underside of the sink. This ensures a clean surface for the new drain assembly.

Goal: Use a specialized pliers wrench to remove the old drain flange and scrape away hardened sealant and debris from the sink's drain opening.