Its very simple. You find a character with Kekkei Genkai and you kill them. However you cant just randomly attack a character, you have to know of thier existence for one and also have reasons behind killing them. To do otheriwse would be to 'meta game' or use OOC knowledge. Remember, what you know and what your char know are two entirely different things.
When you have provided the appropriate storyline and killed said char you must then produce 5000 words of RP details how you had the body part (arm, eye ect) implanted into your body.
YOU MAY ONLY HAVE 3 IMPLANTS!