How to get my IPhone 4 from sprint unlocked to any carrier?

How can I get my IPhone 4 from sprint unlocked to any carrier?

Have Sprint unlock it for you for free. Or pay an unlocking service to unlock the phone for you.
Many local cell phone repair shops, can also unlock phones.

You can't, the iPhone 4 is either a gsm phone or a cdma phone which is what sprint uses. Your phone would need to be flashed not unlocked to a different cdma carrier.

Sprint iPhone 4 can't be unlocked as they don't have SIM slot, thus no GSM capability.