Transfer old Iphone4 to another 4

I have an old 4 that i am waiting until the new 6 comes out next year. I have dropped it too many times and it is on its deathbed. I have my wife's old Iphone 4 she does not use. I tried just swapping out sim cards but that didnt work. Can I basically turn her old phone into mine with my number etc?

via iLounge Forums http://forums.ilounge.com/iphone/279809-transfer-old-iphone4-another-4-a.html