An adjustable wrench, slip-joint pliers, a screwdriver, plumber's putty and a bucket are the basic tools needed to install a drain. Custom or elaborate plumbing installations may require additional tools and equipment.
Use the screwdriver to remove any putty or sealant from around the edges of the old drain. Remove the nut securing the old drain in place with the adjustable wrench. Place the bucket under the drain housing to catch any water that remains in the piping. Disconnect the old drain housing from the drainage pipe with the slip-joint pliers, and pry the old drain up and out with the screwdriver.
Apply plumber's putty around the drain hole and press the new drain flange down into it. Connect the drain housing to the drain flange and secure it in place with a washer and a nut. Tighten the nut with the adjustable wrench until the entire assembly is secure. Take care not to over-tighten the nut to prevent any damage to the surrounding plumbing.
Connect the drain flange to the drainage pipe with a washer and nut and tighten it with the slip-joint pliers. Finally, run water through the newly installed drain for a few minutes to verify that there are no leaks.