How to use straight talk on a galaxy s3 verizon plan

[devilution]

Will I need a Sim card or just root it?

 

[Apanzee]

Buy a SIM card and see if it lets you use the network. If not, then you're SIM locked to the network it was originally on. Unfortunately no one on tom's will help you unlock your phone, it's against site rules. Try the XDA forums. http/forum.xda-developers.com/