I agree with Szakk, I've never been able to force an exit, its always something that happens naturally, I have read about different techniques (rope technique, roll out ect.) but they never did any good for me. When I first started I used to feel like there were two beings pulling me out. lately it usually happens if I become semi conscious or lucid during sleep. But I think its mostly a matter of your state of mind and wanting it to happen. For me anyway.