A GFCI breaker has two lugs for your wires to go plus a white wire that is made into the circuit breaker. If you are replacing a regular single pole breaker with a GFCI breaker you will need to remove both the hot wire from the breaker and also the neutral wire for that circuit from the neutral bar in the panel.
Turn the breaker off that you are replacing. After removing the hot wire just unclip the existing breaker from the panel and take the breaker out of the panel. Depending on what brand of electrical panel you have will determine exactly how the breaker snaps in on the bussbar. Most all brands except Square D QO Series just hook on the side first and then snap right into the busswork on the panel.
The QO Series breakers snap in the same way on both ends of the breaker. On the GFCI breaker you will have a silver colored lug and a brass colored lug along with a white wire coming from the breaker. That white wire from the breaker will tie back into the neutral bar in the panel. The white neutral from your circuit will tie to the silver lug on the breaker and the black hot wire from the circuit will tie to the brass colored lug on the GFI breaker.
Once all these connections are made turn the breaker on and push the test button. The breaker should trip out if it is working properly. Replace the panel cover and that is all there is to that project.
