Google seems to have ignored this feature in the first release of the desktop app at least on the Windows platform.
The process seems to be very complicated right now. You would have to disconnect your account. Reconnect your account and go through the setup process once again and pick a new location for the Google Drive folder.
You would also have to sync everything again as Google would not accept existing files that you might want to copy to this new folder.
Hopefully Google would add this feature to the Drive desktop app in the near future.
If anyone found a simpler/faster method, please tell us about it!