How do you replace the trasmission control module on a 2001 Buick custom century?

To replace the transmission control module (TCM) on a 2001 Buick Century, first disconnect the negative battery terminal to ensure safety. Locate the TCM, which is typically found near the transmission or under the dashboard. Unplug the electrical connectors from the module and remove the mounting bolts. Install the new TCM by reversing the steps, reconnecting the electrical connectors, and securing it in place before reconnecting the battery.