I unbricked my friend's S7 Edge because he tried to flash from G935V to G935U. The device is back to stock firmware (G935V). He wants me to take the T-Mobile G935U firmware and flash it to his Verizon G935V...(He wants to change the region to TMB from VZW). I know how to do this through Odin, but would it be safe and would I need a root to be successful? I've read the stuff on XDA but still have that second feeling. Has anyone ever tried this and were they successful?