It's pretty easy. Remove the grill. Then remove the drivers side headlight. Then you can access the glow plug module. It's right under the battery, screwed into the front wheel well. Disconnect the negative battery cable!!!!! Then you have to unplug two plugs from the glow plug module. Then you can use a 10mm socket to unscrew the positive 12v from the battery and lastly you unscrew the two 10mm nuts that hold the module to the wheel well. All in all, it should take you no longer than an hour, probably closer to half an hour.
While you have the larger of the two plugs off the module, you should check to see if you have any dead glow plugs. Use a multi-meter. Search online or the forum for ways to test the plugs.
Good luck!