If you need to extract the contents of an update package, you can use this command line utility to do so.

Kjs.AppLife.Update.PackageExtractor.zip

Usage:

Kjs.AppLife.Update.PackageExtractor <package file> [options]

<package file>             The update pacakge file (Zip) to be extracted.
                                The contents are extracted to a
                                <package file>_extracted folder in
                                the same directory as the <package file>.

Options
/extractfolder:<folder path>    Extracts the update package to the designated
                                folder.

/?                              Displays this information.

For code-based package extraction, this tool is also available in library format (dll)

AppLifeUpdateExtractor.dll

The PackageExtractor class contains two static methods:

   PackageExtractor.Extract(string updatePackage)

   PackageExtractor.Extract(string updatePackage, string targetFolder)