You will need the special tool. It presses into the fittings and realeases a spring that rides against a collar, then the entire line slips out of the socket, past the spring. You won't need the tool to re-insert the line, only for removal.
The tools are just a piece of plastic that slip beteen the fittings. I have two different types - one is just a small piece that slips betweeen the fitting and the other is sort of "caged" with a hinge that closes a top over the joint when you work. I sort of like the caged version better for fuel lines, as they often have a bit of residual pressure and they keep the fuel from spraying everywhere.
What usually will not work is that siscors looking tool with a different fitting on each end... They are the wrong size (or have proven so for me).
The simple ones usually come on a beaded chain with sevreral sizes and are really cheap...
