How do you install a 20A breaker?

To install a 20A breaker, first, ensure that the power is turned off at the main panel. Remove the panel cover, and locate an empty slot in the breaker panel. Insert the new breaker into the slot, ensuring it clicks securely into place, then connect the black wire to the breaker terminal and the ground wire to the grounding bar. Finally, replace the panel cover and restore power to test the installation.