Ever stop to think about just how important that doorknob-and-lock is to your home? It keeps a house safe whether or not you're there, and it makes a big first impression on your guests. That doorknob-and-lock actually is one of the simplest mechanical components in your home and one of the most useful and important. Yet, unless you live in a fancy custom home or have opted for upgraded hardware in the past, your home probably has a builder's ?basic 101? vintage subdivision lock-set. However, changing a lock-set to a shiny new, safe-and-secure late model is one of the most cost-effective and user-friendly projects you can undertake. If you do it yourself, all you'll probably need is two types of screwdrivers: a flat blade and a Phillips. Just remove the lock-set assembly piece-by-piece, first the knob, then the rose, mounting plate, cylinder and latch assembly. Then install the new lock-set in the reverse order. If you're taking the trouble to replace the hardware, you should upgrade. Remember: the better the hardware, the better the finish, the better it looks, the longer it lasts. And that's the On The House tip for today.