What's legit funny, because it's truly how I approach things problem-wise, is that nothing could be simpler: Just take Material Chunk A in one hand and remove whatever is necessary from it...
Despite Browning's immortal lines the truth is there are many cases where your grasp should be firmly limited by your reach. Professional pipe restoration is one of them. If you don't have the experience don't learn at someone else's expense (you're free of course to trash your own pipes to your heart's content). And if you don't have the talent, and want it done right, send it to someone who does. In this case that would be George; or George; or maybe that guy called George.