OK...

make sure the battery's charged.

person under bonnet: wear eye protection.

check that there's current to the stop solenoid, also that when you apply
current to it you hear it click.  If there's no current or no obvious
action, remedy the solenoid first.

Working at each injector, loosen the pipe union about half-to-one turn -
ideally, you want to hold the injector body still but not always essential.

have an assistant crank the engine, with ignition on.  Observe the fuel
pipes (where you loosened them) and you should see froth and then diesel
squirting out.  for each pipe, once there's no more froth, just high
pressure diesel, nip up the pipe union.  Once each injector has been bled,
and no more air emerges, that cylinder should start firing - if you do 1 and
3 in that order it should, once you've got 1 and 3 firing, run by itself
without cranking while you do 2 and 4.

If you get no fuel at the injector end of the delivery pipes, then the sop
solenoid is not working, or possibly the thing that it pushed inside the
pump is stuck.  Unscrewing the solenoid from the pump should allow you to
test it and see that it operates.

I'm assuming you've primed the pump at this point - there's generally a lift
pump with a lever or other priming device - identify the feed and return
from the diesel pump and having slackened them make sure you get diesel from
both, then tighten 'em up again.

Another thought

Have you ever seen the engine run?

When i rebuilt by 2.5 diesel, it took me about 3 or 4 batteries worth
of cranking before i got fuel through into the right places and
managed to start it.

I've always bled it by working through the fuel system loosining off
connectors and then cranking till fuel came out.