Open the fuel tank and drain all contents into an approved fuel container. Unscrew the air filter cover, either on the top or the side of the Weed Eater. Take the cover and the air filter off.
Unscrew the air filter box from the engine. Unscrew, if applicable, the choke cover plate from the top of the carburetor. Unhook the throttle cable from the Z-fitting on the carburetor, using the pliers.
Unplug the two rubber fuel hoses from their elbow connectors on the carburetor. Detach the screw securing the carburetor to the engine. Take the carburetor out of the engine.
Locate the plastic limiter caps sitting above the adjusting screws for idle, low and, if applicable, high. Twist the limiter caps off slowly and gently with the pliers. If you twist too hard, you risk breaking the carburetor adjusting screws and damaging the carburetor.
Set the carburetor back in the engine. Tighten down its mounting screw. Reconnect the fuel hoses and the throttle cable. Refit the choke cover plate, the air filter housing, the air filter and the air filter cover.