Step 1: Unscrew the screws that fix the upper end of the riser to the digital display, and then turn the display over. Remove all the screws that fix the plastic part behind the digital display, find the communication cable port of the safety lock core, unplug all the terminal, remove the safety lock, replace it with a new one, and fix it.
Step 2: Cover the plastic part behind the digital display, screw on all the fixing screws, and finally lock the fixing screws that fix the riser and the digital display.