If the low beam bulb on the Yamaha XMax 400 blows, it is advisable to replace it as soon as possible. Place the scooter on the centre stand, unscrew the central screw located under the two front headlamps to remove the black mask, unscrew the 4mm Allen screw that appears at the centre of the headlamps and the two at the top, inside the shield under the windscreen, to detach the upper part of the black mask. Unscrew the bolt on the side under the windscreen, open the right glove compartment and unscrew the Allen screw at the top, free the plastic cover at the top and unscrew the side screw that we have uncovered. Still using the 4mm Allen key, unscrew the screw inside the shield; now you can unclip the side of the shield and gain some space to remove the rubber cover behind the bulb, pull out the connector and unclip the metal spring that holds the bulb: these operations are made difficult by the cramped space. Remove it and replace it with a new H7 bulb, taking care not to touch the bulb with bare fingers. Insert it into its housing and secure it with the clip. Reattach the connector and replace the rubber cover. Reassemble the body parts in reverse order of the operations.