Bought some male terminals, crimping tool, jumper harness, and a curved connector from a parts harness, I'm ready to modify the harness.
This is what I am starting with. No bumper harness, and the black horn wire had no connector.
After switching the six wires from the pyramid connector to the curved connector using the male terminals and adding the harness end of the black horn wire, I thought I could finish this tonight. However, I need a female terminal for the other end of the horn wire. Thought I already had some of those. Damn.
Once I buy a terminal, I'll connect these plugs and make sure everything works properly before adding the flasher kit.