According to SIS the 8Cf00339 is the machine S/N for a 935C Track Loader with a build date of December 21, 1988.
Not sure what you need to know about removing the starter, should be somewhat straight forward job.
Disconnect negative wire at battery to kill all power to machine. This step is not listed in the Cat manual but I feel it is very important!
Then per Cat service manual on SIS:
1. Remove the engine side panel, on the left side of the machine.
2. Put identification on the wires that are connected to the starting motor. Disconnect the wires from the starting motor.
3. Remove the three bolts that hold the starter to the flywheel housing. Remove starting motor (1). The weight is 27 kg (60 lb.).
To reinstall:
The following steps are for installing the starting motor.
4. Inspect the gasket for the starting motor. Install a new one if needed.
5. Put the starting motor in position and install the bolts that hold it in place.
6. Connect all wires to the starting motor.
7. Install the engine side panel on the left side of the machine.
Then hook the battery back up and it should be good to go.