Starter problems

[tenderometer]

Have never posted in this section so hello everyone. I am posting on behalf of my Dad as he's having problems with his Series 2 Discoverys starter motor.
He went to start it yesterday and all it did was click and not engage, he hit the motor with a rubber hammer and it then started.
He's thinking of changing the motor all together so is there anything he should be aware of before he starts. Things like which is the best way to disengage the battery?

The vehicle is a:
Land Rove disco series 2
T reg
TD5

Regards
Andy C

[imspanners]

Very common problem, usually with a simple solution:

It could be a lack of power to the starter solenoid caused by a bad connection right on the solenoid itself.
The connectors can go rusty. Disconnect the battery, remove the 12v+ battery wire off the starter solenoid, clean with emery cloth and refit. Also the main engine to body earth, remove that from the bellhousing bolt, clean the connector and bellhousing mounting face with emery cloth and refit.