there is a cap twists off the back, and a white white that has a blade connector (usually coverered by more white material) then a black wire that goes to a screw that is holding down a spring metal tab that holds the bulb in,take the screw out (after paying attention to how it looks assembled) and the bulb should come right out.
unclip the connector and then use a 10mm socket to remove the bolt in the bottom. then push the fog light out through the front of the bumper. it makes it alot easier to get to the bulb. then twist the black cap off the back of it and the wire holding the bulb down just presses down then over.
i have hids in my fogs (which i bought off ebay cuz my truck didnt have them stock) and the hid bulb (that i used at least..h3.) is longer than the stock bulb, so it wouldnt fit in the fog with the rubber seal on back.. so i electrical taped it all up nice n tight
but this might not be a problem for u because i dnt know which type of foglights you have. mine may just be diff than yours cuz i got them off ebay.
but my point is, the hid might not fit in but its easy to rig up. oh and the ballast have to be mounted up in ur fender. from the lights to the ballast is plug and play, and then from the ballast its just pos and neg wires. at least thats how mine was..