I think they mean you have to spend all night pulling on the syringes, tapping on the calipers & levers & hoses, whispering to your bottom bracket and counting your spokes backwards.

Zip-tie the levers to the bars & leave overnight. That works.

yeh. Then refill the top reservoir. It's not ideal. It can give you quite good results.

Protect your grips if using zip ties or use tape instead

Hairbands are good for nocturnal brake bleeding.

shhh Krag, thats a secret!

So following this guide

what part do I leave over night?

Anyone got any idea?

its very simple, stand your bike upright, loosen your brake levers,then make sure that your brake reservoir are level,tighten them back up,and then undo the lids.place a zip tie or hairband over your levers and leave over night,if you can be bothered to watch,every so often you will see a little air bubble rise,after a few hours it can add up too quite a lot of air,and make a considerable difference,you may also have to add a bit more blake fluid depending on how much air came out.

Or, just zip tie your levers as tight as you can to the bars overnight, this compresses any air bubbles and alows them to rise up the hose more easily. When you release the levers in the morning (when you brake the hose is sealed off from the resevoir by a port in the master cylinder) the bubble escapes into the resevoir where it does no harm.

Tends to need doing after a flight for example when the levers might get squeezed on/off a lot when not upright allowing any air in the resevoir to get into the hose.