There have been various recommendations about bleeding a diesel engine in these replies. All well and good, but some simply do NOT apply to YOUR engine.
The ONLY bleeding technique YOU need to know is what is required for YOUR engine.
For example, on my M25 Kubota/Universal, there is a knurled knob on the
injector pump that is very easy to hand loosen while the
electric fuel pump is running to bleed the engine. NO touching of the injectors is ever required.
The later versions of this M25 engine, the M35, is self bleeding.
Notice, I carefully said "On MY engine." I didn't say "No Kubota engine ever require touching the injectors." I don't know that for a fact, so I don't say it.
Yanmars are different engines and require different techniques.
Find out what is required for your engine and do that. Doesn't matter what anyone else does, does it?
Look up
Maine Sail's "Hall of Fail" post on his website and learn why manual fuel bulbs are a bad, bad, bad idea. I don't know why people with Yanmars just don't install fuel pumps and make their lives a lot easier, but we see it here all the time, and on other
boating forums.
Good luck.