If you're still checking in 'maps', the guys over at Reasonable Doubts recently had a go at this topic. They did it in two shows. I find them entertaining. Here are a few hot tips:
There are legitimate problems with philosophy and epistemology. We definitely haven't figured everything out and they see that as a weakness. Don't let them put you on the defensive. “I don’t grant that premise” is a good response to some of the places they will begin their logic. Keep them on the defense, their strategy is offensive. They will transform an unresolved issue into an unresolvable issue, then resolve that you should put your trust in God. The counter is, we can have probable knowledge, unproven knowledge. Don’t let TAG arguments take control, remind them that just because naturalistic arguments can’t provide explanations, it doesn’t follow that God can.
I'm not sure how to handle this suggestion, but they said, emotional appeal is not off the table. Like saying their reasoning is immoral. They view you as a self-deceived enemy so no need to try to get on their good side or try to gain their trust. Play the emotional poker game. http://freethoughtblogs.com/reasonabledoubts/2012/02/22/episode-98-presuppositional-apologetics-part-2/