You will need to get the bulb, open the hood, locate the headlamp retainers, detach the power, take out the old bulb and then replace the bulb. For more instructions you can look at the owners manual.
Underneath the right headlight
Yes
It's behind the headlight.
Pull up on the two small ("L" shaped) slides(on top of headlight ass.).Headlight pulls out.
behind right headlight
By removing the locks that hold the headlight assembly in place you can wiggle the headlight assembly out to gain access to the headlight bulbs for replacement.
The chime is located on the dashboard of the Century. If it does not sound, you may need to have your vehicle's electrical system examined.
It does not have a Timing Belt. It has a chain, that needs no adjustment.
May be computer controlled and not adjustable
Well, darling, to adjust the headlight aim on a 2001 Buick Century, you'll need to locate the adjustment screws on the back of the headlight assembly. Use a screwdriver to turn the screws and adjust the aim of the headlights up or down as needed. Just make sure you're not blinding innocent drivers on the road with your newfound lighting prowess.
Under the right headlight, there is 2, one for high tone, one for low tone.
To adjust the headlights on a 2007 Buick Lucerne, first park the vehicle on a level surface about 25 feet from a wall. Turn on the headlights and mark the horizontal and vertical centers of the beam on the wall. Locate the headlight adjustment screws behind the headlight assembly; typically, the vertical adjustment is on top and the horizontal adjustment is on the side. Use a screwdriver to turn the screws until the beam aligns with the marks on the wall.