Servo

Can anyone tell me how to exchange the actuating pins on these servos? There is a spring behind a castellated washer, is this washer holding everything in place and if so how is it removed without damaging it?
Also, does anyone know what the switch does that sits below the master cylinder, there are two wires to it but both share the same terminal.

Really do appreciate your help and thanks Charles you're a star.
Dave

What have you done to those 3 pictures? - when clicked they stay as thumbnails - themis supposed to get bigger metinks.

Thanks Sean, I've had a play with the pics so maybe these will be OK

Can anyone tell me how to exchange the actuating pins on these servos? There is a spring behind a castellated washer, is this washer holding everything in place and if so how is it removed without damaging it?

The pushrod shoves the valve device inside the servo's tubular part we can see sticking out. By squashing a rubber washer at the same time as the pushrod is applying the brakes master cylinder on the other side of the servo, the servo's power-assistance is generated. The assist is in proportion to the effort on the pedal. It may at least double the pedal push, and some of them treble it.

The spring we can see is there to pull the pushrod firmly back as soon as the brake pedal is eased up or released, thus causing the servo to power itself BACK.

Trouble is, it's the wrong pushrod for the car!

There are several solutions:
The first two are the target:
1. Change the pushrods over, but HOW do they come out?
2. Change the parts of the pedal mechanism to match the new servo.

3. burst into tears then go for a beer.
3.