I want to make sure that I understand what you are asking.
It sounds like you are working on the last line that comes up the passenger side of the engine compartment.
The fuel line that you are currently replacing goes between the hard line, 12, in the diagram and another hard line that comes up on the rear passenger side of the engine compartment.
www.autoatlanta.com/porsche-parts/hardpa...78-82§ion=107-05
If this is right, that is the hardest line to replace, but if you have gotten the bottom fittings off for the replacement fuel line, you are home free. (If you haven't gotten that one off yet, let me know and I can provide some suggestions. )
If you are referring to the intake hard line, #12, then to answer your question directly, yes. Turn the connecting nut that goes into the fuel distributor, counter clockwise.
However, you actually don't need to remove line #12 at all. You can leave it in place and only work on the connector that goes into the male side on the passenger side of the engine compartment.
If this doesn't make sense to you or if you'd like to discuss it in more detail, you can send me an email. I think that you can find it in the membership section -> member list.
Congratulations. You are almost done! (With this job, at least!)