Your green card is depending on your mother's marriage with him. If your mother received green card or removed the condition, you can do the same. He cannot simply "cancel" your green card. If your mother received conditional green card, she may add you when she applies for I-751. If your step father refuses to file joint petition with your mother, your mother will have to divorce him and file waiver of joint petition.
Answered on Oct 12th, 2011 at 12:00 AM