If your trying to get fuel from the rail to the injectors, crack off, and undo SLIGHTLY the pipes at the injector end, and get someone to turn the key, let it run till fuel comes out, then stop and tighten the nut
DONT I REPEAT DONT do that on a DCI, they run at pressures of 300bar and above, so the last thing you wnt is a jet of diesel fuel hitting your hand at that pressure.
The system is self bleeding, just crank it for a bit it will go.
You could prime the low pressure side, one the end of the fuel pipe you will see a little plug in yellow, twist it the way the arrow says, crank it, close it off.