How do you replace wiring harness for headlights Buick lacrosse?

To replace the wiring harness for the headlights on a Buick Lacrosse, first, disconnect the negative battery terminal to ensure safety. Remove the headlight assembly by accessing the mounting bolts and disconnecting any electrical connectors. Carefully detach the old wiring harness from the assembly and connect the new harness, ensuring all connections are secure. Finally, reassemble the headlight assembly, reconnect the battery, and test the headlights to verify proper functionality.