How do I change (and find) the spark plugs 2003 hyundai santa fe 3.5L

A 3.5 V6 Santa Fe has direct ignition, which means each plug has a coil on top of it.
I don't list a 3.3 engine for a 2003 model.

That is what you have to do on a chrysler v-6, also-remove the intake manifold. Be sure and use a new gasket for the manifold. Also check if there is a holding bracket for the manifold on one side or the other, or both as on a chrysler.

I would suspect they are under the ignition coils,if you
can not see the spark plugs

Have a qualified Hyundai Service Technician properly diagnose your vehicle

Turn key on and see if you can hear the fuel pump running.

To locate and change the the (4) spark plugs on a 2003 Hyundai 2.4L 4 cylinder engine:
Remove the (4) 12mm bolts from the decorative plastic engine cover. Remove plastic cover from engine and place it off to the side out of your way.
Standing in front of the car, the (4) spark plugs are located laterally (left to right) in the recessed area underneath where the plastic engine cover was removed.
Note: This engine has (2) coils....They are located above spark plugs number (2) and (3) from left to right.

why would you fix a problem that is not there.if it is fine then enjoy it.plugleads only get changed if faulty.

Remove the plastic cover that goes over the engine (the one with the Hyundai logo).
At this point, you will see the cables that goe to each fo the spark plugs.
Noting their position, remove them.
The spark plugs are ready to be removed, turn counterclockwise and replace with manufacturer recomended ones.

there are 2 covers that are over the plugs the first is the big silver and black cover that has four
10mm bolts remove them and then there is a small black cover that is inbetween the two humps on the valve cover i think that there 6 bolts that holdthat down remove this and the coils and plug wires are visable