Disconnect the battery negative (-) cable in the cargo compartment, ensuring to read the battery disconnection cautions beforehand. Remove the cabin microfilter housing and the ignition coil cover, followed by the ignition coil at the corresponding cylinder of the fuel injector service. Maintain cleanliness when servicing ignition coils, as fuel or oil residue can compromise the electrical resistance of the silicone used in their production, leading to potential coil failure. Next, remove the fuel line to the corresponding fuel injector, taking precautions as the fuel line is under high pressure, which may cause fuel to be expelled forcibly. Avoid smoking or working near heat sources, and keep a fire extinguisher nearby. Ensure the engine temperature is below 40°C (104°F) before working on the fuel system, unscrew the fuel tank cap to relieve pressure, and plug open fuel lines and fittings. Use a clean shop towel around the fitting before disconnecting to manage residual fuel pressure, and to reduce pressure, place a towel over the injector and gently tap with a wrench. Maintain a clean work area to prevent contaminants from causing system malfunctions, seal all fuel system openings with protective caps, and replace high-pressure fuel lines if they have been tightened 10 times. If multiple injectors are removed, ensure each is reinstalled in its original location. Unlock and remove the electrical connector, then remove the fastener and hold-down bracket before taking out the injector. Seal the injector and fuel rail connections with caps and plugs from the BMW special tool kit. If an injector is stuck in the cylinder head, use the appropriate BMW special tools to carefully remove it, and once removed, install sealing caps on the injector tip and fuel line connection, which can be obtained from the BMW dealer parts department.
