I replaced my headlights and fogs with sylvania silverstars which worked great for about 1.5 years. Well, I had one of the fog light bulbs explode and now there is a good deal of condensation inside the foglight. I am wondering how I should go about replacing the bulb (or whole assembly) and if the condensation will be a problem.

 

The condensation getting in there is what blew your bulb. I would clean out the light assembly, and then install a new bulb will some di-electric grease around the joint where the bulb locks into position. Mine have been like that (I have the 2003/2004 style lenses which replaced the defective 01/02 style) for two years without any issue.