Originally Posted by Army

The best way to turn the crank is to use a 27mm socket on the crankshaft pulley nut. Only turn this nut as though you are doing it up - so standing in front of the engine looking at it (looking towards the back of the car) you turn it clockwise.

If you find that the compression hinders your progress it is safe to remove each of the glow plugs from the cylinders. Do not remove the injectors unless you plan on replacing the heat shields as these are a fit only once items.