I have a 300SL with a bad contact in the key switch (to the starter solenoid).

The NSS checks OK and the car will start with a screwdriver at the solenoid.

I'm looking for some advise on the removal and replacement of the key switch. I assume that it comes out from behind the dash and I'm wondering if I'm going to need specialized tools for the job. I couldn't find anything helpful on line and I'm wondering if there are any helpful tips I might want to know before I get started with this. It looks like it's not going to be a walk in the park.

Any comments will be appreciated.

 

Well, my 96 tried that dirty little trick, start sometimes not crank other times...
I wired a "push button" under the dash where I could easily reach it and just "push the button" with the key in the "ON/Run" position... easy to wire up and no one will be able to start your car with out knowing about it...

Try it! Cheap and easy!

The "Old Timer"

 

Find a power source at the fuse box under the hood to provide "fused" power to your push button and run the other side to the solenoid... you'll need to drill a small hole up under the brake pedal or run it through a grommet if you can find one down there...
Put a small piece of 1/4" rubber hose on the wires where they go through the firewall...

Works everytime...