If you need to return to stock for any reason, you will need to boot to FASTBOOT and relock your bootloader with:
reboot to fastboot again, and it should say **RELOCKED** at the top
put this file
on a microSD card as is (it should be named PH39IMG.zip), power down phone, insert microSD and boot back into bootloader. it should automatically find the zip file and flash the stock image (this includes recovery, system, everything stock. its the same as running the RUU, only you dont need a windows machine for it
after that, if you want to re-unlock your bootloader, you will need to run:
fastboot flash unlocktoken Unlock_code.bin
just like the first time you unlocked it
I can provide the stock rogers the same way if needed.
Attached is the stock boot.img for the ATT Vivid.