First, you need to remove the front bezel, loosen the two screws on the front of the Ue box, and remove the bezel. Next, loosen the two screws on the front of the LMB module. Pull the two metal levers apart. And pull the LMB module out of the U-box chassis.
Check the connectors at the back of the LMB module for any damage before inserting it back. Insert the new LMB module into the U-box chassis. And press the two metal levers back into the original position to ensure that the module is fully inserted. And fasten the two screws of this module.