http://www.corvetteradios.com/
Here ya' go... I stumbled onto this website while looking for info on those darn Delco display bulbs that burn out frequently... Seems as though it is a very simple bulb replacement and easy to do. This website sells those Delco display bulbs, and they also have a step - by - step tutorial on how to remove the cover from the radio, and how to replace the bulb.
Even though the website title says " corvette radios ", there is a section for Pontiac radios. When you see the opening homepage, click the grouping of bulbs that will be in the center of your screen; that will take you to the proper section that you need.
Hope this helps you out. Have a awesome and safe holiday everyone!!!
Tommy; from Massachusetts