Basically you would just save the config to flash and tftp it to your machine. Review and modify the config if required (to change port numbers etc if required) and upload via tftp to new system.
You can also view detailed steps posted here by David: https://supportforums.cisco.com/discussion/10872816/copy-configuration-uc520-uc540
-Terry
Please rate all helpful posts and mark the thread as answered if you have no other queries