here are some basic instructions that might help and probably can be modified to your needs:
PIAA Fog Light Installation
If you're thinking about installing fog lights onto your car, here is a step to step install guide. PIAA is by far the most popular but these instruction apply to most other brands as well eg. CATZ, Road Boy..etc.
First disconnect the negative terminal of your battery.
Now test fit the desired location for where the lights are going to be placed and mark the position with a pencil or small piece of masking tape. In some cases you might have to remove the bumper to make the job easier (Civics).
Clean off all dust and dirt and securely fix the mounting bracket to the desired location. You can also use double sided sticky tape that PIAA and CATZ provide with their units. HOWEVER given the popularity of theft for these fog lights, I would DEFINITELY not suggest this!! Mount the fog lights on the mounting brackets last, after everything is installed.
Run the wires through a secure location (make sure it doesn't snag on anything and away from the fan blades and boiling hot headers). Attach the negative lead (in most cases BLACK COLOR) to the negative lead of your battery or ground it to the chassis of the car.
Next, securely mount the fog light relay somewhere in the engine bay. Connect the positive lead (PIAA 1400 uses a fat WHITE lead) to the positive terminal of your battery. Make sure the other lead on the relay is also grounded to the negative pole of the battery or chassis.
Now you have to find a light that has a constant supply of power to then which in most cases will be your front parking lights. Tap the positive lead of the front parking light (PIAA provides a splicing connector). This will provide power to your fog lights.
Finally, run the fog light switch into the inside of your car through any hole of the firewall, or you can carefully drill a hole. Make sure the hole is lined with a rubber grommet to protect the wires from cutting and shorting. Ground the switch to a metal part of your car chassis. Find a nice location on your dash to mount the switch. You can drill a hole in the dash to "flush" mount the switch.
Mount your fog lights back on the mounting brackets, connect the wires, and put the bumper back on, if you took it off in step 2. Reattach the negative lead of your main battery terminal.
Now turn on the fog lights, make sure they are aligned properly (aim at a wall 20-30 ft) and enjoy!
This last step is optional! Mount a hidden video camera on your grill so that you can catch the thief who is going to steal your newly installed fog lights.