I'm able to see a small detent in the receptecal part of the new replacement alternator. This detent is probably holding the connector in place.
Removing Plastic alternator connector, cant get it to budge. on 1997 Toyota 4Runner
You need to keep working at it. There is nothing holding the connector into the alternator but the tab. Good luck
Thanks for your input. I'll continue to gently work on it . will give it a shot of non conductive cleaner lubricant to see if that will help.