How do you change a used iPhone number to your own number?
I bought an iPhone from my sister, it was hers. She didn't like it, so she sold it to me. I was wondering if there was a way to change the number: I don't want to use her #. There is no sim card in it.

you will have to tslk to the phone company
I think you need to reset the device and re-sync it with the computer as if it were completely new. It should walk you through once you plug it into your computer and open itunes.
first of all you need to have a SIM card and that SIM card has to be activated by the service providers to your phone. that is the only way to change the number. case closed !