How many labor hours are necessary to change the spark plugs?

That seems like a fair price and a fair time - it took me the better part of 6 hours the first time I changed them - the front three are easy, but the rears are under the upper intake manifold. In the 2002, to take off the upper intake manifold you need to take out the air filter housing, rubber hose, battery (may need to be cleaned with baking soda and water), disconnect all the electrical connectors on the manifold, disconnect all the vacuum hoses, preferably take off, inspect and regasket the IAC valve, the EGR valve and the throttle body. When taking off the intake manifold you need to follow a pattern for removing the nuts, then regasket the intake manifold and put it all together to the torque specified in your manual for all removed parts. Easy, but time consuming. Also be sure to get a locking extension so the spark plug socket come out of the tube. Also buy and apply anti-seize to the threads and dielectric to the electrical connectors (the top of the plug and the coil.)

SHOP MANUALS I READ SAY 1 HOUR I WOULD TRY ANOTHER PLACE PLUGS ARE NOT THAT HARD TO CHANGE AND $80.00 AN HOUR IS A LITTLE STIFF IN MY BOOK

max hourly labour charge should be $65....at $80, your definately at a dealer. It actually does take a good 2-3 hours because the spark plugs on the 3.0L engine requires dismantelling the air intake manifold and a bunch of other wires and cables. See www.fordforumsonline.com...someone posted the step by step should you want to save some money and do it yourself.