programing a 2000 trailblazer remote

My remote is not working to good i thing the buttons conductive coating are worn out inside. I ordered one on ebay and need directions to reprogram for my car.
I did a search and one person was not to sure on directions.

thanks for the replys

follow the instuctions on this thread
http://www.automotiveforums.com/vbulletin/showthread.php?t=96957&highlight=keyless+entry+programming