So I bought an alternator and the plastic tab broke, how do I remove the metal pins to replace into another tab?

 

Do you mean like this?

 

I’m not sure if there are pins holding them in.

 

See the little plastic tab down in the hole alongside the connector pin? Pry that toward the outside (away from the metal pin) with a needle or xacto knife tip. Then pull the wire and pin out the back. Do not pull on the wire until you have the tab moved out.

Be sure to put the wires into the new plastic shell in the proper places.

 

Or if you don't want to shred the end of the tab, the other method is a small flat tip jewelers screwdriver from the back side (wire side) of the plug to push the tab out. Usually slides between the tab and the spade.