A pedestal sink is fairly easy to install if your basic plumbing—a drain line going into the wall, and hot and cold water supply lines with stop valves—is in place. Keep in mind that the pedestal is not very wide and may not conceal the supply lines. Moving the supply lines closer to the drain is a big job, involving both plumbing and wall repair. The solution may be to let the plumbing show.

Shut off the stop valves and check the faucet to make sure the water is off. Unscrew the nuts holding the risers to the stop valves and pull out the risers. Unscrew the nut holding the tailpiece to the P-trap. If you have a wall-hung sink, you may have to disconnect two bolts holding it to the wall; if not, simply lift it up and out. If you have a vanity, lift out the sink top and pry away the cabinet. You may have to patch and paint the wall.

Don't rely on the pedestal to support the sink bowl; think of it instead as a decorative piece. Drill test holes to make sure there is solid wood framing behind the drywall or plaster, to which you can firmly anchor the bowl's bracket. If there was once a wall-hung sink, there should be a framing piece already installed. If not, cut a hole in the wall, install a piece, and patch the wall.

After you've set the bowl on the pedestal, position it against the wall and mark the location of the mounting bracket. Screw the bracket firmly to the wall and check that it is level. Slip the bowl onto the bracket and check that the pedestal fits snugly beneath. Reposition the bracket if necessary.

Remove the bowl from the wall and place it on a table to attach the faucet and drain. Follow the manufacturer's instructions when attaching the faucet; set the faucet on top of a plastic gasket or a bead of plumber's putty and tighten the mounting nuts from underneath. Make sure the faucet is aligned correctly and does not look crooked. Attach flexible risers to the two faucet inlets.

Apply a small rope of plumber's putty around the drain hole, slip the drain body through the hole, and tighten the mounting nut underneath. Insert the pivot rod into the body, and screw the retaining nut fairly tight—you should be able to move the pivot rod without much effort. Slide the stopper rod down through the faucet from above, and attach the clevis to the pivot rod as shown. Adjust so that you can lift and lower the stopper using the stopper rod. The stopper should be able to seat all the way down into the drain, and raise high enough for water to drain easily.

Set the bowl onto the mounting bracket and check it with a level. Attach the drain line, using either chrome or plastic parts to attach a P-trap that leads from the drain body to the drain line in the wall. Even if you are re-using old trap pieces, install a new rubber gasket at each connection. If the new sink is at a different height than the old one and you have to cut a new piece or two, use a hacksaw to make straight cuts. Cut and install carefully, so that there are no crooked joints. Tighten all the nuts by hand, then use channel-lock pliers.

Attach the risers to the stop valves. Tighten the nuts by hand, then use pliers. Turn on the water and check for leaks in the riser connections and from the drain. As a final test of the drain, fill the bowl with water and then lift up on the stopper. If you see any leaks, tighten the joints. If leaks persist, disassemble and try again.

When you've eliminated all leaks, slip the pedestal under the sink bowl. You may choose to caulk the joint between the sink bowl and the wall.