A community member shared this method of resetting the RICOH THETA V. You need to have the camera in developer mode to follow this process. You can put the camera in developer mode by joining the partner program, which is free as of 11/2/2018.
EDIT: Added Jan 27, 2019
Since this will return the THETA to factory settings, images will also be deleted! ! ! Save your data before resetting.
This will affect the time setting of the THETA. Time is set when connecting with the basic RICOH THETA smartphone app. It is recommended connecting to the basic RICOH THETA smartphone app before use.
Since the THETA is returned to factory settings, development mode is also turned off. Please turn on development mode using the RICOH THETA desktop app.