MGM GRAND LAS VEGAS?!?

I booked a room in the west wing tower king (MGM)...but I'm not sure if I did the right thing. Should I change to the grand tower? Are they the same price? if they both cost the same amount, then I'm pretty sure I could "exchange" the west wing for the grand tower (right? I'm mean they are the same price). And I'll probably exchange during my check-in. Besides, there are 3 guests and the west wing has 1 bed....but i'm sure we can sleep together on the same bed (we are family)....I really need help! But if the prices are different, I'll have to pay extra to "unbook" the room at west wing...please help me find the price ranges for both!!!