Can't start engine, battery is good and all you here is a clicking sound?

The contacts in the starter motor solenoid are worn, the clicking that you can hear is the solenoid being pulled in, but not making contact to allow the main battery voltage/current from getting to the starter motor. Their are 2 things you can do to get you out of trouble if you are stuck in a place and no assistance is available.

Rock the car back and forward whilst in gear, stop and try again.

Tap the side of the starter motor cover with a piece of wood or soft hammer. This will wiggle the contacts and allow for starting.

These may get the car up and running, but ultimately the contacts will have to be replace.This job is usually not difficult or expensive, and is the first thing to check and replace, before replacing the whole starter motor. It is a much more cheaper option then replacing the starter motor assembly.

If you can find the starter motor, the solenoid is the small round or triangle box on top or to the side of the starter motor, usually with two small wires going to it.

BELOW ARE TWO CONTACTS FROM A LANDCRUISER 1HZ ENGINE. THE LEFT ONE IS FULLY WORN OUT AND THE RIGHT ONE ABOUT 50% WORN.