Removing the headlamp is the easiest way. Two long threadbolts hold in the headlamp. You might have to jiggle it a little to get it out.
UPDATE:
Look in the manual. It explains that you have to partially remove the bumper in order to get the headlight assembly out. I know its a pain I've had to do it before. Don't yank too hard, it's plastic so it WILL break. Also, be careful that you don't bend the metal out of shape.
how do you replace headlight bulb in a 2001 celica gts
Are you asking how to replace the entire headlight assembly -OR- how to replace just the headlight bulb? Just the bulb.
beat the car with a bat
open the hood and pull out the bulb
To replace the headlight bulb on a 2001 Cadillac DeVille, first, open the hood and locate the headlight assembly. Turn the headlight bulb socket counterclockwise to remove it. Gently pull out the old bulb and insert the new bulb, taking care not to touch the glass with your fingers. Finally, reinsert the socket into the headlight assembly and turn it clockwise to secure it.
Replace headlight bulb only when blown.
To replace the headlight bulbs in a 2001 Acura CL, first, open the hood and locate the headlight assembly. For the bulb you need to replace, twist the bulb socket counterclockwise to remove it, then pull out the old bulb. Insert the new bulb into the socket without touching the glass, twist it clockwise to secure it, and reconnect the wiring. Finally, test the headlight to ensure it’s working properly before closing the hood.
On older vehicles you replace the entire headlight. On the newer vehicles you just replace the bulb unless the headlight assembly is damaged.
Open Hood. Remove the cover from the headlight by prying up the keeper. Remove the metric 13 nuts holding the headlight in. Take out headlight and replace the bulb. Reinstall the headlight and reinstall headlight and cover.
To replace the headlight in a 2001 Mitsubishi Galant, first, open the hood and locate the headlight assembly. Remove the screws or clips securing the assembly, then carefully pull it out. Disconnect the wiring harness from the old bulb and replace it with a new headlight bulb, ensuring not to touch the glass with bare hands. Finally, reassemble the headlight assembly and secure it back in place.
http://www.bombaydigital.com/boxster/projects/headlamp/
How do you replace headlight bulb on 2004 Mazda Tribute?