You do not need to do anything to transfer ownership of a Pico. The operating software is now Open Source and freely available. There is a version available for download on our website here:
http://www.eigenlabs.com/downloads/latest/pro/
There is also a more up to date community release maintained by Mark Harris which supports the latest versions of MacOS and has a number of improvements, you can read about that here:
http://www.eigenlabs.com/forum/threads/id/1501/
There is a community discourse server run by Mark that has lots of conversation on it here:
https://community.polyexpression.com/