Since you didn't say what year Wrangler you have, I'll add to what PTaylor said. On my '06, fold the rear set forward, push down on the bar that runs along the bottom, and pull the seat out.
Regarding headlights, if cleaning the connections doesn't work for you, it is very easy to replace the entire headlight. The stock lamps are sealed beam, so they don't have replaceable bulbs. Three torx screws hold the bezel, then three more hold the headlight on with a ring. If you want to upgrade to halogens, several companies make very nice headlamp replacements. I like my KC H4 Conversions. Others prefer Hella's.