Will someone that knows how, add this to the knowledge center?

If the flare nut on the flex line does not loosen with reasonable force. Cut the flex line and rotate it off the steel line. To make it real easy, heat the connection and the heat will blow the rubber line out of the fitting. You can then loosen the fitting with your fingers AFTER it cools. Use glasses to be safe. Once they are separated, you can try to loosen the flare nut on the steel line. NOTE it is not necessary to have it loose. Just rotate the flex line onto the steel line and tighten. Then connect the caliper end of the flex line.

This has not been checked by Frank, but it works.