My fuel line (from the injector rail to the fuel filter) has a major leak because I ran over something that pinched a hole in it. It's a 240 with bosch FI.

PROBLEM: I can't get the gas line unscrewed from the fuel rail.

What is the secret?

It won't budge. I got a line off of a parts car but had to hacksaw off the end of the rail because it won't unscrew either and I had wasted a lot of time. Even though I sacrificed a fuel rail I can't get the fittings apart even on the replacement with it off the car. I've used PB Blaster and penetrating oil and tapped on the parts til my arm is tired. I've put it in a vise, tried big wrenches for leverage. The metal just starts to get butchered. I am going to ruin parts if I don't figure out a way to take them apart.

QUESTION: how do I separate the fuel line from the injector rail?