STOP!
Don't use pliers! Go down to the auto parts store and buy a fuel line disconnect tool. They are usually just a few bucks, no more than $12 for a pack of six or so. They look like little plastic "discs" of various sizes and colors. And they have a plastic part that sticks out. The disc will have a slit in it so you can put it over the fuel line where it attaches to the fuel filter. Then you push the disc inwards on the fuel filter with the plastic part that sticks out going into the fuel filter a bit and an inter-locking mechanism will release. Be sure to not break the plastic disc when you put it on the line.
You also use these for the fuel lines attaching to your fuel rails in the engine compartment.
Be sure to release the pressure in your fuel lines before you disconnect the fuel filter or be prepared for a mess.
To release the pressure: Go into the trunk area. Behind the driver's side near the rear tail light under the panel is a small box with a red button on it. Unhook the wire harness attached to it (underneath it) and then start your car. If the car starts, it will run out of gas in a very short while but most likely just turning it over will drain the pressure from the lines.
When you are done replacing the fuel filter re-attach the wire harness. Don't mess with the red button, it has nothing to do with this.