How do you change a cell phone number to another cell phone?

If this is a GSM phone then simply switch the simcard to your other phone (if the phone is from another carrier then you must first get it unlocked) OR if this is a CDMA phone then you need to call the carrier and ask them PORT the number for you.,How do you change a cell phone number to another cell phone?
Depends on the company. Some, all you have to do is swap the SIM card and others you have to call and give the ESN number located under the battery and a rep will activate it so all of your calls go to that device.How do you change a cell phone number to another cell phone?
This would depend on your cellphone provider, you should give them a call and ask for more details.