You can download LUP from SourceForge. Consider grabbing both the full installer and the source code.
There are several requirements for installing this software:
When running the program, you must use an account that has a domain trust to the WSUS server and is part of the WSUS Administrators group. If your computers are in a workgroup, you can create a trust by creating saved network credentials for a user with appropriate permissions.
Next step: [Create_and_export_the_code_signing_certificate]