A quick note: The back plate of the keypad side of the lock on the exterior of the door has a sticker which includes the serial number, six digit programming code and two pre-programmed four digit user codes. The lock must be disassembled to a point the exterior of the lock can be pulled away from the door and the information on the sticker made note of.
This link will take you to the page that you need to get started:http://consumer.schlage.com/Service-Support/Pages/InstructionandManuals.aspx
Then scroll down to this heading on that page:Electronic Security-Keypad Entry Flex-Lock FE595/Keypad Entry Auto-Lock FE575 Documents
There's a wealth of info under that heading. You will be able to see a PDF file of the original print instructions, as well as a video of how to install the lock. This is useful because there should be a sticker to be found on the backside of the keypad, with the code number that you need to reprogram the lock, which i noted above. This installation video (fourth item down) will be useful to allow you to disassemble it and view the sticker. This is also a great time to change the 9-volt battery!
The eighth item under that same header is a video which walks you through how to reprogram the keypad to your new code, using that programming code that you found on the backside of the keypad.
Also, you will find "Keypad Programming Guide", etc. links which are PDF type files, giving you a "picture" of the print instructions.
A note about the PDF files: If you cannot view a given file, you need to first install Adobe reader. You can get the free download from here:http://get.adobe.com/reader/
Good luck,and please provide feedback if this helps!