How do you start 2010 Nissan Altima with mechanical key?

To start a 2010 Nissan Altima with a mechanical key, first ensure the vehicle is in park (for automatic transmissions) or neutral (for manual transmissions). Insert the key into the ignition and turn it to the "Start" position. Release the key once the engine starts. If the engine doesn't start, check if the key is functioning properly or if there are any issues with the battery or ignition system.