Here's a schematic. If you don't understand it, it would be best to just have a stereo shop do it. If the stereo shop doesn't understand it, they don't know what the hell they're doing and you should take it to a one that does. All the materials you'll need can be found at your local electronics store. Radio Shack may have what you'll need as well, but they seem to be a bit over priced.
If you wire this up correctly your bumper lights will work like the factory intended them to with the switch in the off position. Once you flip the switch though your bumper lights will come on and stay on acting like fog lights. The unique part about this schematic is, you won't have hyper blinker when you use your turn signals, AND the bumper lights will still blink!