Boot device into bootloader mode by power device off then holding volume down and power until bootloader mode / fastboot mode starts on the screen

open RSDLITE program from motorola and select remove-amazon-bloat.xml

click start to remove all the reinstalled amazon junk and ads on the lock screen

Note this should work without unlocking the bootloader. 
But if it fails i know for sure it will work with the bootloader unlocked. 