Replacing or repairing the radio antenna wire

A previous owner cut the antenna wire in my car. The wire that carries the radio signal. I am trying to replace it. I can see most of the run at this point. The place I need a bit more access to is behind a piece of trim. How do I remove the piece of trim that I highlighted in the picture below?

I would be satisfied if I could repair the wire but everyone I talked to said they are not repairable.
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Never mind I fixed the wire. It appears that piece of trim is riveted in place.