How can I quit the Beta Programme and restore the official software?
You can cancel your participation by going into the Samsung Members app and going to Settings > Galaxy Beta Programme > Deregister.
You can re-install software by using the PC version of Smart Switch. Once the software is re-installed, the device will be reset and all data that was generated during the Beta Program will be erased.
Smart Switch - link
direct link for Windows
All data which had been backed up before installing the beta software can be recovered, but there may be limitations in recovering data that was created after installing the beta software.
*Note: please use Smart Switch PC to backup important data before anything else
If you need assistance, Samsung Service Centres support the reinstallation of official software.