How do you change engine computer for a 1988 Chevrolet celebrity?

To change the engine computer (ECM) on a 1988 Chevrolet Celebrity, first disconnect the negative battery terminal to ensure safety. Locate the ECM, typically found under the dashboard on the passenger side. Remove the mounting screws and unplug the wiring harness from the old ECM. Install the new ECM by reversing the process: connect the wiring harness, secure it with screws, and reconnect the battery.