It's best to do this shortly after Passiflora seed is ripe (pick when ripe and let set for 2 weeks). I'm not sure how long you have had the seed, but it won't hurt to give it a try with the dry seed. Soak the seed pods in enough water to soften them up (about equal volume of water and seed) enough to be able to mash the outer pods into a pasty mixture. Place the mush/pulp (pod/seed/water mixture) into a clear cup and cover with plastic wrap. Set in the sun or a warm place for about 3 days. All this is to ferment the seed so that fusarium disease is killed. Passiflora seed is very vulnerable to this disease.
After fermentation has taken place, use a sieve to seperate out the seed in your kitchen sink. Put the seed on a paper towel and let dry. Just prior to sowing, soak the seed in warm water for 24 hours. When planting, barely cover the seed in about 1/8" to 1/4" soil or seed starting mix. The seed will germinate best at around 68-75F in slighly moist soil.
Hope this helps. If you have questions, give me a holler.