There has been a lot of discussion on changing the back lighting on the dash instrument panel and the consensus here was they are soldered in and a biotch to replace.

However, I ran across this thread on another forum:

http://www.gmfullsize.com/forum/showthread.php?t=24726

According to this, it's easy. I did note that this truck is not a D-max, but is a 2006 Silverado. Has anyone had the cluster out on a 06 to see if the lights are soldered or plug ins?

They are soldered. Only the 2002 and earlier clusters have replaceable lights