Locate the aerator at the end of the spout. Most manufacturers include the flow restriction device as part of the aerator.
Place several layers of painter's tape around the aerator to protect the finish from the pliers.
Grasp the aerator base firmly with a pair of slip-joint pliers and turn it counterclockwise. Loosen the aerator enough that you can remove it completely by hand.
Lay out the pieces of the aerator on the counter and locate the water restriction device, which is a small round plastic piece with one or more holes in it. Remove the device, reassemble the aerator parts and reinstall them on the end of the faucet. Remove the painter's tape.