I went through something similar last weekend.
I had lows and DRL's, but no high beams. I used
this thread
on a flakey turn signal switch to find that the contacts in the switch to the high/low lever were being difficult.
Cleaned everything up, and got them working again.
Actually I had to do it twice as I was not thorough enough the first time, and when I put it back together I had DRL's and high beams, but no lows... Second time was much faster...
Also I tweaked the switch contacts a very little bit to give them more spring pressure.
The worst part of the job is removing the airbag (not hard, especially once you figure out how to do it, just fiddly), other than that it's pretty straight forward. Removing the lower steering column cover is kind of a pain as well.