If you are bleeding it anyway, use a screwdriver or something to press in the black plastic collar around the central silver pin on the slave cylinder side of the coupling to release any pressure. It will be stiff if there is a lot of pressure in it and will spurt fluid out when you release it.
As for the collar and which way it goes, the pins should face down into the connector as its them that stop it coming apart until the plastic collar is pushed in, squeezing them flat.
They actually clip together pretty easily so I dont see how you could be having trouble unless one of the valves is jammed (the plastic ring I mentioned above or the central part of the male side from the master cylinder.
It is possible to get rid of the coupling, but not simple. The fittings are the same as brake pipe fittings, but there is no way to fit a coupling to the plastic pipe from the master cylinder so you need to bin that and fit a bit of copper pipe, which involves brazing the copper to the nipple that clips into the bottom of the master cylinder - dont mess if you cant do that sort of thing. I did it and results were less than optimal I think due to the copper being too rigid and not compensatin for movement between the engine and the bulkhead like the plastic does. Ideally you would use a flexi hose.
Mine is fecked and will have to stay that way as there is no way I can be arsed stripping it again to change out the pish slave cylinder I fitted when I changed the clutch. I need to bleed it every two weeks, which I can do in about 45 seconds now. I wrapped the bleed nipple threads in PTFE to stop air being drawn through them and fitted a meter or so of plastic tube to the nipple which I leave on and the end is coiled up behind the battery with a basic one-way valve on it. I just reach under the pipework to get a wee spanner on the nipple, slacken it a 1/2 turn, drop the end of the tube into a bottle of old fluid and pump the pedal a few times, wedge it down, tighten the nipple, stow the pipe again and top up the fluid in the master cylinder.