Q: How to replace low pressure ac service port.

Plastic from the low side service port cap is inside the threading of the service port. I tried to clean it out, but I haven't been very successful. I bought a thread chaser, but it didn't fit because the plastic is really caked in the port. I might buy a smaller one and see if that might help. If I can't get the threads clean, then I just want to remove the entire port. The problem that I can see though is that it doesn't have any flat sides that I can use with a socket or a wrench. It looks completely smooth all around. How can I remove the entire port (assuming that it is threaded into the line) to replace it if I need to?

My car has 160000 miles.
My car has an automatic transmission.