(redirected) Upgrading an alienware x51 PC?

Hello, i have an early 2012 alienware x51 with gtx 660 and am in dire need of an upgrade. I am hoping to purchase a gtx 970 with a minimum power requirement of 500w, i know that my model has an AC adapter and not 500w worth of power, i am planning on switching cases as well. So how do i upgrade to this new card? Do i need to buy a new powersupply and motherboard? that would not be preferable and this card is a must. so please help me with this problem.