Never touch the bulb glass with your bare fingers. Grease and oils from your fingers vaporize in the heat and will leave a deposit on the reflector, which may damage it.
Remove the round low beam rubber cover from the headlight housing.
Remove the connector from the bulb.
Remove the bulb by pressing it slightly upward and then pulling it out.
Insert the new bulb in the socket. The bulb's guiding pin should point straight up.
Press the connector into place.
Put the round rubber cover back in place.