To disassemble the gopro is very simple.
There are 4 screw inside the battery chamber, there is a plastic glue in what looks like a heat sink inside the gopro, just use a little bit of force to remove it.
Once you remove de back plastic of the gopro, now is time to remove the front.
There are 3 screws for this step, to on the rigth and one in the left near the tv out connectors. Unscrew it and its done.
Now you need to weld the wires like it was the 2.5mm jack.
Use a multimeter to check the right position to soldering the wires.
Once done this step, plug the toothpick to simulate that there is a 2.5mm plug and you may use the TV Out.
Here is the video from my assembly