How does one test and then install a headlight ignitor and ballast on a 2002 Acura TL?

To test the headlight ignitor and ballast on a 2002 Acura TL, first disconnect the battery, then remove the headlight assembly and access the ignitor and ballast. Use a multimeter to check for continuity in the ignitor and ensure the ballast is receiving proper voltage. If either component is faulty, replace it. To install, reconnect the new ignitor and ballast, secure them in place, reassemble the headlight assembly, and finally reconnect the battery to test the headlights.