Yesterday I rooted my Verizon GS3 on 4.4.2 using towelroot. Didn't seem to have any problems. Installed SuperSU, updated the binary and disabled Knox. Installed Titanium Backup. Installed busybox and then the safestrap apk. Installed recovery in safestrap. GPS has been on the fritz for about a week and now it isn't working at all so I went to do a factory reset and got the message saying "system software not authorized...". No good. So I can't reset. I want to just completely unroot, reset the phone then potentially root again.

I'm pretty new to all of this. Can someone help me with the steps to unroot? When I try to uninstall busybox it tells me it may screw up the phone. When I go to uninstall SuperSu it tells me it may screw up my phone. I don't want to brick it. Can anyone please help?