To replace the Instrument Cluster bulb, the instrument panel (I/P) cluster needs to be removed first. Undo five 7.5mm screws (I/P cluster). Unclip the i/p cluster rear cover plate gently prying on the tabs with a screwdriver that is then removed. Next, remove the bulb and base assembly by turning the bulb 1/2 turn counter clockwise and pulling it outwards and take the bulb out of the base by unscrewing the base by pulling outward. For installation, begin by inserting the bulb into the base and then place the bulb and base combo to the cluster and turn the bulb 1/2 turn clockwise. Snap carefully the rear cover plate back onto the i/p cluster and lastly re-install the i/p cluster. That is, this procedure is for incandescent bulbs only because the replacing of light emitting diodes (LEDs) is not possible individually. For led or soldered-in incandescent bulb replacement, get the cluster to ac delco service center.