Before I break something: any tips on body to rear axle brake line connector removal?

Just an update- Success! Nothing broke.
I think it was the heat that did the trick. Thanks to all for the input and advice.

I'm still an absolute rookie mechanic but thanks largely to this forum, I'm getting through this stuff with minimal breakage and learning a ton in the process.

I'm a lot more confident that I can get through almost any job given enough time, repair manuals and the forum. I just need to start them early enough in the winter because I'm still slower than a 170 /6 in a C-Body running up a hill. :D