I'm trying to change my sprint galaxy s4 model sph-L720 to verizon. i have verizon servicesbut my verizon phone is broken and i was given this samsung gs4. I was told that they can be converted. I have a sim card for my verizon and there is a slot in the samsung for a sim card. So is this possible? Can i switch carriers to where i am using the samsung gs4 as my verizon phone?