3.4L Injector Rail Removal

I am trying to replace the lower intake manifold gasket and I am stuck trying to remove the injector rail. I have disconnected the return fuel line and also the nut cunnecting the supply line to the rail. But I am not able to separate the supply line from the rail. What am I doing incorrectly? I am reluctant to use too much force to separate the two. HELP!!

Try using some penetrating oil like PBBaster. If you got the return line at the bottom of the fuel pressure regulator off then the supply line should come off. Also, use the proper wrench so you do not strip the nut at the fuel feed pipe assembly.