On my 77 they were a plastic coated trim piece that I just broke off and trashed. The trim pieces were held on with some kind of black epoxy or glue. No matter what I tried the damn trim just wouldn't come off without delaminating. I considered replacing it, but after it was all said and done I think it looks better without them on.
As far as heading went, I fitted a hair dryer and a heat gun, but no luck.
I almost feel like the car would be better off with the channel filled in.
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