un-root HTC one

[Guest kudosmotion]

I installed the switch Rom and all well then I did a factory reset and it took me to twrp recover and I restored the original Rom that I backed up before installing the switch Rom. now I want to remove the custom recovery and super user. put in layman's terms I need to unroot and lock the bootloader as the camera on the device has a fault and has to be returned for warranty repair. please help.