It's pretty easy if you know some electrical and you have a voltage meter. you need to find the foglight relay under your hood and access the wires on the bottom of the box. once you have the wires there should be 4 wires one positive one switch wire and one headlight wire the last wire is the out put. you need to test and find the headlight wire and cut it about a few inches from the relay . (check the tech section on my site for wire colors) once you have the wire cut you need to extend it and connect it to your parking lights once you have that done your lights will come on with your parking lights instead of headlight
http://www.g20style.com/wirep10.htm
I've done this a few times at work for customers