How do you adjust the tappets on a fiesta 1998?

To adjust the tappets on a 1998 Ford Fiesta, first ensure the engine is cool and remove the valve cover. Then, using a feeler gauge, measure the clearance between the tappet and the rocker arm for each valve. Adjust the tappet clearance by loosening the lock nut and turning the adjusting screw until the proper clearance is achieved, then tighten the lock nut. Finally, recheck the clearance to ensure it is within the specified range before reassembling the valve cover.