This trophy is titled "I Can Rebuild Her..." and it's for having Nirvana (your doll comrade) broken down 3 times in one round. While it says you have to decommissioned her, it's really just having her break down and stand back up 3 times in one round. You can move her while holding D (X on default controls) and she only takes damage when D is held. Simply move her away from you and let the second controller, foe or your friend beat her while you hold X in order to break her three times. Upon seeing her surrounded by sparks for the third time the trophy should be won.