When I got my 1998 E-350 the dash lights didn't work. I didn't know why, and am not the best at troubleshooting chassis electrical, so I took a guess that the moving part (dimmer) would be the most likely to break, and decided to throw one part at it (new headlight switch) before doing anything else. Long story short, a new headlight switch fixed the problem, and it's been fine for over two years now.
Anyway, reason I am posting is that it was a bit of a pain, but not that bad to replace the switch. But my dash panel is in two pieces, so I only had to remove the one associated with the gauges (it divides into two pieces before it gets to the powerpoint and cigarette lighter). I recently helped a buddy who has a 2003 and his dash panel was all one piece - I could see where that might be more of a pain.
But if you do have the "crack" and the two dash panels, it wasn't too bad (just don't do what I did, and not disconnect the battery, then poke a wrench up in there to try to avoid taking the switch bezel off, cause a spark, and then have to replace the passenger side door lock actuator (in my defense, someone had told me that disconnecting the battery would mess up the engine computer, and I've gotten better at things since then
).