We did this project several years back so I don't have pictures to show you the transformation. However, if you will refer to the child kitchen post (http://greeneacreshobbyfarm.blogspot.com/2011/05/child-kitchen.html) the process for inserting the faucet and the sink is the same.
I purchased the copper sink on eBay from Mexico. The faucet had to be set to the side to fit properly but I like how it added some character as well. The buffet had three drawers down the middle. We removed the back of the first drawer and left the front as a false drawer. Next we added plumbing.
The bottom two drawers still fit and were functional with the plumbing in the back.
Antique buffets and even chests of drawers can make perfect bathroom vanities.
1. Select your piece of furniture and purchase a sink that will fit on top. Remember you are going to need plenty of room for your faucet too. ( I had to sand and refinish the buffet I used. I also used three coats of polyurethane on top to seal and protect the wood. Allow to dry fully between each coat of polyurethane and sand lightly before each application)
2. Use the sink template that comes with your sink and trace it on your antique piece of furniture.
3. Remove any piece that may interfere with cutting. (I had to remove my top drawer and detach the back from it. I used scrap wood to put the false drawer front back in place when all the cutting and sink installation was done.)
4. Drill a pilot hole in the area of the oval or circle you plan to start cutting.
5. Starting in the pilot hole, use a jigsaw to cut out the hole.
6. Use a hole saw to cut out the areas for your water lines and pvc pipe from the drain.
7. Use your faucet template to cut out the holes for installation.
8. Place a bead of caulk on the furniture top near the opening to allow the sink to drop in place. (Don't use too much or when you drop the sink in the excess will squeeze out on your furniture top)
9. Install your faucet and plumbing.
Parties I linked to: