Unfortunately the metal one does require a special tool. I have send directions below. Now, the tool can be bought at nearly all parts stores or some rent it. The tool may not look exactly like the picture. This tool is not expensive at all. They have plastic ones for under $5 at most stores Like AZ or Advance etc. I wish there was another way but it is needed to prevent damage.
After relieving the system pressure, a small amount of fuel may be released when servicing the fuel lines or connections. In order to reduce the chance of personal injury, cover the regulator and the fuel line fittings with a shop towel before disconnecting. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete. NOTE:
IMPORTANT: Always maintain cleanliness when servicing fuel system components.
INSTALLATION PROCEDURE CAUTION: In order to reduce the risk of fire and personal injury, before connecting fuel pipe fittings, always apply a few drops of clean engine oil to the male pipe ends.This will ensure proper reconnection and prevent a possible fuel leak.During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated.