Raise the headlights by turning the light stalk to the first position and flashing. Make sure the lights are off, but are raised. Then, pull out the "RTR 30 A" fuse from the fusebox in the front boot. (see here for fusebox locations.
CAUTION: Unless the power is disconnected, there is a danger of the headlights suddenly retracting and causing injury
Loosen the four screws, two either side of the ornament and remove the ornament. Then, loosen the four retainer screws and take out the beam unit together with the retainer, then unplug the connector and remove the rubber cover.
If the connector is tight, widdgle it.
NOTICE: Never attempt to loosen the headlight aim adjusting screws
Release the bulb retaining spring and remove the bulb. Install a new bulb and the bulb retaining spring
To install a bulb, align the tabs of the bulb with the cutouts of the mounting hole.
These images are taken from the Users Handbook.