How do you replace ecm on 98 eclipse?

To replace the ECM (Engine Control Module) on a 1998 Mitsubishi Eclipse, first disconnect the negative battery terminal to ensure safety. Remove the ECM cover and disconnect the wiring harness and any associated connectors. Then, take out the old ECM by removing the screws or bolts securing it, and replace it with the new unit. Reconnect the wiring harness, secure the ECM, and reattach the battery terminal before starting the vehicle to ensure proper functionality.