How does one replace the fuel filter on a 1998 Buick century? What degree of difficulty is it for a non mechanic ( but has some experience w/ basic car maintenance)?

The fuel filter is under car by gas tank. Use ramps or jack up car and support it good.
Loosen gas cap to relieve any pressure in system.
Twist the connector 1/4 turn in either direction to loosen any debris. Squeeze the plastic tabs on the end of the connector and pull the connector apart. Repeat for the other connector.(some models might have a screw in connector on one side) you will need a couple of wrenches.
Remove filter mounting bolt, unhook the tab from the receptacle in the frame and remove filter. Installation is just reverse.
snap the connector back on and pull to make sure it connected. You will need a drip pan to catch the fuel when you dsconnect the lines and what's in the filter.

Very simple. First locate the filter (usualy found under the car on the sides near the rear). All you have to do is release the pressure from the tank. This can be done by simply removing your gas cap. Useing line wrenches remove the fitting from both sides of the fuel filter. Put new one on but make sure to hand tighten first to make sure you do not cross thread and strip the fitting. Put gas cap back on. Now you will need to prime the filter. This can be done by simply turning on the car (do not start it) a couple of times so the fuel pump can push gas through the filter. Now you may start the car. It may hesitate a little bit but thats okay. After you the car running look under the car to make sure you are not leaking any gas. Now you are done. Good luck!