As Eugene says, its easy, in the manuel on site there is a good description on how to open the magic box, desolder and solder the lamps is easy, and change all of them, new ones are brighter than the old ones.
Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!