A word of warning... you may want to either wear some saftey goggles (the kind that have foam round the lense and "seal" against your face) or just be sure you are out of the way when you disconnect the line.
Last time I did it, I was having a hard time getting it off, which resulted me in not being careful of where my eyes were when I finally did. Gasoline + eyes = ouch.
Here's an example of the tool you need:
Easier to do that than try to describe it.