silverado brake light switch

I am trying to change out a bad brake light switch on my 94 silverado. The switch is located on the brake pedal but is in a place behind the steering column that makes it very difficult to get to. I can not get the retaining clip off because I cannot see the clip to see how it comes off. It is like trying to do this blindfolded. It does not feel like an ordinary retaining ring. Can anyone give me an idea of how this clip attaches or at least what it looks like please. I thought that I was in for a simple task (ha).