How do you change glow plugs on a 2004 6.6L Duramax diesel?

To change the glow plugs on a 2004 6.6L Duramax diesel, first ensure the engine is cool and disconnect the battery. Remove the intake manifold for better access, then disconnect the electrical connectors from the glow plugs. Use a deep socket to carefully unscrew each glow plug, replacing them with new ones, and ensure they are torqued to the manufacturer's specifications. Reconnect the electrical connectors and reassemble the intake manifold before reconnecting the battery.