I'm swapping rear trailing arms and need to remove the brake and emergency brake lines

Is fluid going to spray everywhere if I remove the brake line?

For the emergency brake, I removed the 15mm bolt on the little cover on the hub and can see where the cable goes into the hub but don't know how to get it out


Also, what is the ball joint plastic piece connection? Is there a trick to getting the socket out of the ball without breaking the plastic?

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-Dan
1983 240D AT, 163K running on VO, "The Patience Tester"