Is their an easier way without using candles?

How do I invite a demon into half of my soul without going into ritual? Or into my whole being?

How do you become a demon or half demon? I've heard you can be only a demon not half because you must be born half to be half. So how can you become a demon. And also I've felt someone or something on me every night since I dedicated to satan and when I look no one is there is a demon trying to...