Its not hard. Just wire them into the drl relay instead of the headlights. Or even better, relay them from the ignition on wire, then they will be on any time your car is on. Although you will look like a ricer.
I guess the simplest thing you could do would be to just pull the drl fuse (its in the panel infront of the battery) and just leave your fog lights on. Only thing I'm not sure about is I dunno if you have to have your headlights on to have your fog lights on. My car didn't come with fogs so I wired in the switch by itself. That would be pretty easy for you to do to, just wire the existing relay for your fog lights into a different switch, so you wouldn't have to turn your headlights on.