Help! Gamestop BB 070 Xbox 360 RT and LT soldering help

I managed to get my hands on a Gamestop BB 070 Xbox 360 controller and i need to make the RT and LT work as buttons on my arcade controller.

And as far as i can understand and according to these images:

I should wire the Red GND on the front with the Right Trigger spot on the back to make the trigger work as a button. Am i missing something because it is not working.

Any help will be greatly appreciated!