How do i tell my mom i want to live with my dad?

Okay im 15 and me and my mom do not get along, in the divorce plan it says we choice where we want to live because they didnt want to mess up our social life. but ive never lived with my dad bc they just got a divorced last september and the house still hasnt sold. I've slept at his apartment before but never more than 2 days. i donnot want to live with my mother anymore, she treats me horrible. I dont know how to bring it up to her though? any thoughts? or how to tell my dad?