Sprint Phone on Alltel Network

So I've been doing some reading..And I see that people have gotten other carriers phones such as Verizon to work on alltel since they are both CDMA and i cant just use a simcard. I can get a used motorola Q off a girl i go to school with for 75.00 I heard if you program the SID to a certain number and flash the phone with alltel's software for the Q since they carry it also it will be able to be activated. Can anyone shed some light on this for me and tell me how to do it?