Step 1: Gather Necessary Tools and Equipment

• Replacement headlight bulb (ensure it is the correct type for the 2019 BMW 3 Series)
• Flathead screwdriver (if necessary)
• Gloves (preferably latex or nitrile to avoid touching the bulb with your bare hands)
• Microfiber cloth (optional for cleaning purposes)

Step 2: Ensure the Car is Safe to Work On

• Turn off the engine and remove the key from the ignition.
• Allow the headlight to cool down if it was recently on, as the bulb can get very hot.
• Engage the parking brake to prevent the car from moving.

Step 3: Access the Headlight Compartment

• Open the hood of your BMW 3 Series. To do this, pull the hood release lever located on the driver's side dashboard under the steering wheel.
• Once the hood is released, locate the hood latch lever under the center of the hood's front edge. Push it to fully open the hood.
• Find the back of the headlight assembly. This is usually in the engine compartment, directly behind the headlight you wish to replace.

Step 4: Remove the Old Headlight Bulb

• Locate the headlight bulb cover. It may be circular or rectangular, and it protects the bulb compartment.
• If there are any screws or clips, use the flathead screwdriver to carefully remove them and take off the cover.
• Disconnect the electrical connector from the bulb by gently pulling it off. Be careful not to use excessive force to avoid damage.
• Unscrew or release the retaining clip (depending on bulb type) to remove the old bulb. Carefully take out the bulb from the holder.

Step 5: Install the New Headlight Bulb

• Take the new bulb and, wearing gloves, handle it by the base. Avoid touching the glass part with your fingers to prevent oil residue that could shorten its life.
• Insert the new bulb into the holder, ensuring it is securely seated and properly aligned.
• Reattach the retaining clip or screw back into place, securing the bulb.
• Reconnect the electrical connector to the new bulb.

Step 6: Reassemble the Headlight Compartment

• Replace the headlight bulb cover, securing it with screws or clips if applicable.
• Ensure the cover is properly sealed to prevent moisture from entering the headlight assembly.

Step 7: Test the New Headlight Bulb

• Close the hood securely.
• Start the engine and turn on the headlights to verify that the new bulb is functioning correctly.

Step 8: Final Checks

• Check for any flickering or alignment issues. If the light doesn’t turn on, double-check the connections and ensure the bulb is seated correctly.
• If everything looks good, perform a final inspection to ensure no tools or parts are left in the engine area.