Get a bleed nipple spanner it makes it easier.
Somehow I've never got around to getting one of these.
I use a ring spanner or socket to crack the bleed nipple loose but not open, then fit the bleed pipe and use an open-ender on the nipple during the bleeding process, then once the pipe is off I snug down with a ring - but as Colin points out, they don't need a big heave.
