You should define what you mean “take the top off the faucet”. At the end of each faucet spout where the water comes out there is a small screwed in device about 3/4” in Diameter, that is the aerator, inside it there is a screen that catches the small debris that collect in the piping. Use a pair of pliers or a pair of Channel locks padded with a small rag to prevent scratching the aerator and rotate out (righty tightly and lefty loose/ you are looking at it upside down. Blow it out and re-install. Or go to your local hardware store/ Lowe’s/ Home Depot and purchase a new one only a couple of bucks each.