one of the most common repairs on faucets is the replacement of the rubber washer located on the bottom of the valve unit first make sure you turn off the water supply at the stop valve underneath the sink then turn on the faucet until the water stops flowing next remove the handle you may have to pry the decorative cap off first with a screwdriver or sharp pointed knife to expose the screw remove this cap very carefully in order to prevent breaking the pressure prongs which hold the cap in place then remove the decorative bonnet with a wrench once the packing nut is exposed remove it by turning it counterclockwise if the packing nut does not turn easily tap the wrench to loosen it next remove the stem and washer assembly it is sometimes easier to replace the handle on the stem to provide a better grip for pulling the stem out once the valve unit is out remove the old washer by removing the brass screw that holds it in place do this carefully if the brass screw is old and corroded it may break apart when you're trying to remove it apply pressure towards the valve unit while turning slowly next install a new washer and a brass screw if necessary reassemble the faucet parts and put the unit back into the faucet housing tighten the packing nut and then put the handle back on once everything is back in place turn the faucet off and the water supply valves on then test the repair if you still get leaking try tightening the packing nut or you may have a wrong size washer in the end you will have a trouble-free faucet that will save you money on water costs and the repair itself