Within the fittings which are molded on to the end of the fuel lines (the two between the tank and the fuel fiter), there are plastic rings embedded within the fitting. The fuel line disconnect tool (usually sold in a package of rings in varying sizes) is the preferred tool, but you can supposedly remove the fuel lines without the tool.
Through a slot in the fuel line fitting, you can see an orange ring in one line, and a green ring in the other line. Most people I have talked to on this forum have said that you can remove the lines by simply pushing on the colored ring with your thumbnail, through the slot in the fitting. Do this while pulling the fitting off of the filter.
I believe that the fuel line from the filter to the engine uses a "conventional" fuel line retaining clip. You should be able to just pull the clip out of the fitting, then slide the fitting off of the fuel filter.
Whatever you do, do not try to pry or lift the colored rings out of the fittings. Not knowing how these fittings worked, I attempted to pry them out. Now the dealer wants $450 for parts and labor to fix the problem I created.
If you need them, you can get the fuel line disconnect tools at Sears, although due to the tight clearance between the fittings from the tank and the fuel filter itself, the fuel line disconnect tool might be difficult to use.
More info... http://www.ranger-forums.com/forum2/...ight=fuel+line