What I have read so far gives me the impression that you have no clue on how to bleed brakes 4:. That is not something that someone should try to explain to you on an INTERNET forum. I don't mean to insult you but bleeding brakes is not a non-life threatening project like sticking on some plisti-chrome bling. You need a manual or a video like on YouTube. That brake fluid is highly corrosive and you are in a situation where the whole system has to have new fluid and be purged of all air. That system is linked and that piston coming out is going to cost you a lot of aggravation and $$$. You may even need to loosen banjo bolts to remove air.
Ya have 7 of those little gizmo's. The 8th one is the clutch.