I find it easier to only loosen the rear brake line so that the fitting can spin on the pipe. Then I remove the banjo bolt from the master cylinder. As the say assembly is the reverse. The fitting is hard to pull out and to start because the flare exceeds the thread diameter and hangs up.
You can dress the flares once you get them out. The rear line out of the master is hard to pull. I have a broken (split 3/8 UNF die and I've put it around the fitting and then turned it off thus cutting a bit of a thread in the flare edge just to get the line back in.
Provided just the right amount of pipe is sticking out of the die when you make off the flare - it should not be larger than the 3/8" thread. Trial and error to get that right amount - but it's ~ 3/16" above the die surface.
I'm sorry, my memory was a bit cloudy. It's not so much the flare. It's the fitting itself. Probably from over tightening the leading edge of the fitting swells out past the minor diameter of the thread and hangs up.
Are new fittings available over there? We are left to reuse the old ones and I figured cutting a light thread was better than removing the offending material thus making it weaker.
Ah yes - old fittings can swell up at the tip - I always use new, they cost next to nothing. But again - the old fitting can be dreesd down with a swiss file.