Pontiac 2004 GTO - Manual (Page 238)

After replacing the bulbs, remember to reinstall the
radiator cover and the four screws.
1. Open the hood. Access the bulbs by following the
previous instructions.
2. Turn the dust caps
counterclockwise and
remove from the rear of
the headlamp
assembly to gain
access to the bulb.
3. Remove the wiring harness connector by squeezing
the two tabs on the connector and pulling the
connector down.
4. Remove the old bulb
by twisting the bulb
counterclockwise.
5. Carefully without touching it, install the new bulb by
reversing Steps 1 through 4.
6. Check the light operation.
5-48