Raymarine type 2 linear ... need help

[nonam]

Please note I do not need advice on how to ship the unit to Paymarine.Ok
Also,advice to try and get info from Paymarine is bad advice.Ok
The unit has sufered long term drowning.I have opened it up and it looks terrible.But I am not ready to give it up.The ram still moves smoothly .
First,I need help to understand the clutch.It is fixed to the rear cover.It is an electro magnet.I dont understand which part moves when it is energised.I cannot manually move anything back and forth on the fwd part of the clutch which is next to the drive belt.It goes round but I cant see how it engages.
I am thinking there are no moving parts on the electro magnet?

The 2nd thing I need help is removing the rear plate from the electric motor.The plate rotates.The shaft rotates.The front plate rotates.I think the brushes somehow prevent me pulling off the rear plate.

Any hints from someone who has done it?