Here are the steps to remove a sink drain:

1. Clear out the work area. Open the doors of the cabinet to gain access to the bottom of the bathroom sink.
2. Locate the nut that attaches the "P" trap to the tailpiece pipe connected directly to the sink drain.
3. Take off any accessories or covers on your drain.
4. Use a wrench to take off the nut that attaches the drain to your sink, which is usually under something like a strainer.
5. A drain plug is typically held onto your sink by screws. Use an adjustable wrench to loosen and remove them.