If the ones behiind the computer display are like those in used to backlight the radio faceplate, then RadioShack will have them. There very small 12v bulbs with long, non-insulated leads. You'll have to turn and pull the bulb assemble to release them from the circuit board. You then need to unwrap the wire leads from the bulb holder and then remove. Replace with new bulb in reverse order. The literature that comes with the 2-pk of bulbs says they have a life in the order of, due to vague memory, thousands of hours...perhaps less due to the voltage regulation level of 14.5-15v could have something to due with it, defects aside.

As another has mentioned, if this is something want to do just once or best chance at such, replace all the bulbs while you have things apart. I haven't had to remove the panel yet, but an hour sounds good to me.

Goodluck