That looks like AC Delco PT1866 connector?
or more likely Sumitomo HX040...
You'll need the right terminal extractor tool:
https://www.amazon.com/Removal-Conne...dp/B0BVBHS5LG/
Terminals are held in by white plastic lock.
Poke extraction tool in to release lock
http://www.cycleterminal.com/termina...procedure.html
Once lock is removed, depress plastic tab below terminal to release it and pull out back side
Link to original page on YouTube.