I used these pucks.
http://www.vleds.com/accent-lighting/round-puck.html
Followed this
http://www.gm-trucks.com/forums/index.php?/topic/146836-GMT900---Footwell-Lighting
http://www.vleds.com/accent-lighting/round-puck.html
Followed this
http://www.gm-trucks.com/forums/index.php?/topic/146836-GMT900---Footwell-Lighting