Use a penknife etc to pop the end cap; be careful though, there is a spring in there so be ready to control the release.
Switch & LED assy is ~$10.00 at a dealer.
I had a short in the under dash/steering column area that caused LED to malfunction. As opposed to the "flashing" LED that signifies tranny problems.
more on this @: http://www.atcdg.com/TechBulletins/bull_135.htm