The gear selection parts are going to require 5mm leds, proper resistors, and soldering. If you're up for the project, then by all means do it. 
Here is some info on it if you choose to do leds: http://www.v6performance.net/forums/6g-exterior-interior-mods/148766-my-gauges-work-progress.html
Here is some info on it if you choose to do leds: http://www.v6performance.net/forums/6g-exterior-interior-mods/148766-my-gauges-work-progress.html