While dome lights and other interior vehicle lights require only bulbs that operate on low voltage, similar to all other bulbs, they will burn out over time; it may be therefore necessary to replace the dome light bulb in your Lexus IS300 should it burn out. Doing so is quite a short process, requiring only a few minutes and some basic tools.
Use a flat-head screwdriver to gently pry up one edge of the dome light border. The border plastic will click as it is pulled loose--it is simply clipped in.
Pull the other side of the plastic border down, very carefully removing the whole border assembly.
Use a Phillips screwdriver to remove the two mounting screws that secure the plastic bulb cover. Be careful not to strip these screws, as they are made with soft copper.
Pull the cover off the bulb housing and gently remove the bulb--it is secured in a simple holster, and will come out easily.
Slide a new bulb into place, being sure to match up the larger plug end size with its matching counterpart.
Replace the bulb cover and its two mounting screws, once again using a Phillips screwdriver.
Press the plastic border into place, as evenly as possible. As you near the end of the border edges, the plastic will click into place.
