First you need to remove the waste trap (or P trap) and the sink strainer. To do this proceed as follows:
- Place a bucket under the trap to catch the water that will come out once the trap is removed.
- Loosen the slip-nuts at each end of the trap with a pipe wrench or channel type pliers.
- Remove the slip-nuts and the trap. If you have PVC piping, note how the possible nylon washers are oriented.
- Dump the water in the trap into the bucket. Water will also drain from the disconnected ends.
- Once the waste trap is disconnected you'll see a large nut that holds the sink strainer in place. Remove the nut.
- Using a putty knife, scrape the left over plumbers putty used to seal the sink opening.
- Make sure the sink opening is cleaned of all left over putty.

