One-piece cultured marble and onyx vanity tops are found in many homes. That's where the sink bowl and top are molded in one piece. They're easy to clean and look beautiful -- until the sink develops a major crack or a serious ding. When this happens, many think it's time for a whole new top, but you can replace just the damaged bowl with a new self-rimming sink made of vitreous china, cast iron or acrylic. Here's how: first turn off and disconnect the water valves under the sink and disconnect the drain assembly. Use the new sink template to mark a cut line for the new opening. Be sure the rim of the new sink is large enough to conceal the old faucet holes in your top. Then use a jigsaw to cut out the old sink bowl, and seat the new one in a bed of silicone caulk. Since you've already removed the old faucet, this might be a good time to consider a new one. You've saved the day and made a damaged one-piece top look good as new. And that's the On The House tip for today.