Default [Q] Need help with warranty please.

Verizon just offered to replace my brother's S3 to an S4 due to a charging issue. The binary counter shows 1 so he might get charged for the S4.

When he was on 4.2, I rooted and attempted to flash a custom recovery, which failed with a Verizon message. Since then he received the 4.3 update which made him lose root.

I am having him use saferoot to regain root so he can use TriangleAway to reset the flash counter...

On OP it says

"Samsung Galaxy S3 Verizon UNLOCK BOOTLOADER"

Does this mean I won't be able to do it unless we unlock the bootloader? Does anyone have any suggestions on the best way to get this thing back to where Verizon won't know anything was done?

Thanks!!