How to refurbish a bulkhead connector?

If your bulkhead is smoked, why would you assume that any part of the rest your harness isn't compromised. Replace/inspect every inch of it.

My car did that, nearly burnt down. On installing the new harness I found several wires hidden inside the old one that were fused together and shorted or nearly so, miles away from the bulkhead connector. If you're going to the trouble to inspect it that far (which requires removal), stab in a new one.

BYPASS THE CHARGING CURRENT PAST THE BULKHEAD CONNECTOR WHILE YOU'RE AT IT.