Well, here's the front of my recently-rennovated computer case. By 'rennovated', I mean "replaced old-and-boring blue LEDs with the multicolor color-changing LEDs of coolness.

How I managed this was to:

1. Remove the front of my computer case. There were four screws holding it firmly in place. It then snapped out.
2. Unplug the case wires that were plugged into the motherboard
3. Remove lightbars, which were held in with faux-metallic brackets
4. Replace LEDs with Color-Changing LEDs
5. Test the LEDs, and seal it all up with electrical tape
6. Reinstall lightbars and brakets, reinstall the front cover, and reconnect the wires.

See more about these fun little LEDs here. The case front has 4 LEDs in it, so each side has a top and a bottom LED, making some interesting colors in the middle. Even more interesting, the little airbubbles in the plastic lightbars glow two colors: one for the top, and one for the bottom.