Close the gas valve on the grill tank, turning the knob on top clockwise.
Raise the lid of the Charmbroil and remove the cooking grates and lava rocks or ceramic briquettes while wearing work gloves to keep your hands clean and protect against sharp surfaces.
Unscrew the lock nut on the underside of the grill where it holds the burner assembly in place.
Pull the old burner up and toward the front of the grill to remove it from the appliance.
Insert the two tubes on the bottom of the new burner into the two holes on the inside bottom of the grill. Turn the burner toward the back of the grill to angle the tubes down into the holes so that the threaded bolt on the bottom of the burner enters the smaller middle hole between the two holes for the tubes.
Insert the open end of each tube over the nozzles on the back of the grill's control panel.
Twist the locking nut onto the threaded bolt under the grill and tighten with pliers to hold the burner in place.
Replace the lava rocks or briquettes in a single layer inside the grill and place the cooking grates on top.