First thing is you need to make a 3-5 inch wire with a male connector and a 6mm circle end.
I love shrink wrap.
Blue wire = Brake light. Green wire = Run light.
I use files to make sure all my grounds will be good.
Looks ready. Also note that this was painted factory Green over the factory Orange.
The Black wire is the stock lighting fixture ground. Put the new ground wire you made on the same ground bolt as the Black wire.
What the ground wires look like with the taillight assembly installed.
The very bottom male connector gets grounded and the top male connector gets the Green wire connected to it.
Using the ground we just created, we connect the Blue brake light wire to it to ground it out. I like this way because you dont have to cut the original wiring harness.
Everything wired up properly.
Brake light becomes your run light.
Done and now the electrical system is more reliable.