My bathroom sink faucet has decreased water flow. I read that I should remove the aerator to see if there is any sediment in it. How do I remove the aerator? What type of wrench should I use and what is the technique? Should I turn counterclockwise or down or what? Thank you

Usually you can do it by a tight grip with a dtry hand. You could also use a strap wrench or, if flast sided, a an adjustable wrench like a crescent wrench. As you look down onto the faucet arm you are reaching under it so your motions will be reversed. Move your hand clockwise which will actually move the aerator counterclockwise

Bob gave you a excellent answer. If you need to pull the areator to clean the screen here's a diagram to help you put it back together. Good luck, Tom