OK, thanks for that.
For the temperature light to come on the thermostat switch has to work.
I would suggest you check the element first to see if it's open circuit.
If the element is ok, Isolate the power to the appliance and take the rear panel off.
Hook the multimeter to the element connections.
Restore the power, set the clock if necessary, and check to see if it's being powered.
If it's not, I would suggest checking the wiring at the selector switch and the switch itself.
If your thermostat has connections A, B and C, and if the thermostat light is on C, let me know.
If you are fully convinced that it's the thermostat, inside the oven look at the rear panel.
The temperature probe will be clipped to the front panel or nearby.
(You may need to take out the rear panel inside the oven to release it).
Once you release the temperature probe, feed the capillary and the probe out of the hole in the oven.
From the rear, take the probe out, you'll see as you take it out how to fit the new one.
It's not difficult and you don't need to disturb the insulation material.
Check it out, see what you find.
Hope this is of some help
Let me know how it goes or if you need more help