Yesterday I got sprayed with garter snake musk and I need to feel better about myself

My car does not always start, and the code says this was the issue. The connection to the battery is pristine and silver AF. So I wanted to take this thing off and look at the connections to see if it needed to be replaced or if there is another issue.

But I can't look for corrosion or replace it if I cannot get it off.

The things seem fused together. And I do not know what to do to safely get them separated.