I have searched this board and others and have not found a way to change the 6 digit unlock code from 222222 to 000000 in the SPH-I300 (to go form Sprint service to Verizon).

Can this be done from the handset only or does a service tech have to hook into the phone to change this?

Service tech has special software to change this, it is not an option you can normally do. However there is no reason to change it as it doesnt matter what the spc code is when you go to sprint or verizon