Sounds like Mistercamp's approach was a more elegant version of mine essentially opening the high pressure side and letting the prime function do the rest - not sure if the mightyvac was actually used to pull a vacuum or was just a catch can for the waste fuel. I was reluctant to remove the glow plugs as tssacav and others have done due to the requirement/recommendation that they only be removed when the engine is hot

Yes, pull a vacuum with the hand pump. This helps remove any air in the lines. Just be aware the ISTA function ribs for like 3 mins, so it can pull a bit of fuel.