I used override key to open e swipe locker. How do I reset the code???

SOURCE: Digital Electronic Security Safe S2120.

You will probably have to call a locksmith who specializes in digital safes, or you can contact hardline and give them the serial no. of the save and proof of purchase to get the code or key. You will probably need proof of purchase for the locksmith to.

SOURCE: I need to change the batteries and reset the pass

How can I program my electronic keypad lock when the instructions with the programming code have been lost?
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 number is the programming code referenced in the information for changing the entry code.

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 installation video (third 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! Batteries should be replace about every three years.
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.
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!