2013 SS brake lines installation, help?

Leuz

Hey FolkZ,
tl,dr; I am trying to install SS brake lines (ZSpeed) on my 2013 370z (sports package)

Problem: the 10mm nuts, connecting the stock rubber lines to the hard lines on one side and to the caliper on the other, seem to be stuck and I don't seem to be able to unbolt them off. I don't wanna pull to hard as I'm afraid to screw up something and, honestly, I'm also afraid I'm doing it wrong (even though it seems a really easy job to do).

I know these have changed from the previous years, has anyone tried to install them on a 2013? Have you experienced the same issues?

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2013 PW 370Z Touring+Sport, NAV
Tint 35% side, 18% back | RJM clutch pedal | ZSpeed SS lines | Stillen Gen3 CAI | Fast Intentions HFC and TDX 12'' CF CBE | UpRev