The diff adjustments are not hard to do if you follow the workshop manual and make a few special tools.
You will need to make: a peg spanner to move the adjusting nuts; machine a round bar to help measure the pinion protrusion; make a variety of press tools from bar and pipe all of which you can do in the metal shop at school.
The only special tool you will need to buy is a magnetic base and dial indicator, which are very cheap nowadays and can be used to set the front wheel bearings and time the valves in the engine as well.
PM me if you want to see some photos of the tools I made when I did mine,
Cheers Charlie

