Repairing a faucet diverter is not a hard task, so hiring a plumber is not mandatory. Turning off the main water supply is not also necessary. This task, however, requires a new diverter to replace the old one.
It is important to first determine how the diverter is attached. Using an Allen wrench or a hex key is necessary if the spout is attached to the wall. Covering the drain with a washcloth helps to prevent any falling screw from going down the drain. If there are no screws, a person should turn the spout counter clockwise until it comes off. It is important for the new diverter to be similar to the old one.