There is one person on .ms that has done it.
Looks like this.
http://www.ducati.ms/forums/attachme...9&d=1244077401
Thread
Anyone change the 998 gauge cluster lights to LED's?? - Ducati.ms - The Ultimate Ducati Forum
The bulb type you need is "Wedge" also called "W5W" bulbs. Do a google search on W5W LED and you should get TONS of internet shops.
Those are the lamps for lighting the gauges.
If you want to play with the warning/signal lamps, those are the smaller W3W bulbs. Not sure if anyone makes LEDīs that size..
//amullo