If you are talking about the electrical slide switch and not the lock mechanism, the book says to drop the steering column for access. I did that my first time and I had enough trouble getting into the right possition the first time that I learned enough to replace it with out dropping the steering column the second time.
First time took me like 5 hours, second time took me 30 minutes.
I think I followed the DIY online instructions, or the instructions that came with the electric ignition switch, I forget which it was.
Biggest problem is getting the little bugger locked down in just the right spot. Tends to move as you tighten the lock nuts down. If it is not in exactly the right spot it will not start or won't go into the ACC mode....etc. Be careful not to bend the actuator rod that goes into it.