I did this when I accidentally farked up a left shifter.
No problem, you just take it apart, remove all the bits associated with shifting, button, lever, internals, and you are just left with a brake lever.
There's videos on youtube for campy shifter dissassembly if you've never done it before.
There's sometimes a buggy.
How many drivers does a buggy have?
So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.http://www.youtube.com/watch?v=GekiIMh4ZkM