Depends on the style of ambi safety.
A Swenson style safety has a protrusion that extends downward under the grip panel. Remove the grip, as per the previous post. Some, however, do not. Removal is a matter of pulling the right side free from the dovetail inside the pistol where the shaft meets with the left side lever.
If you are looking to replace it with a single side safety, it will require a gunsmith to fit the new safety to the sear.