beta software removal
thanks to nEuDy
Preparation steps:
(optional) Save your "user.config" file at
C:\Users\AppData\Local\Vrgineers_Inc\Somnium_VR1_Tool_Url_xafvawsk4qahexnro0luybdbbszblizh\1.0.4.109\
(use the file only for the same beta tool,
not older or newer versions, as it might not be compatible)
Start SteamVR (HMD does not need to be plugged in) and go on PC to the Menu > Settings:
at "Start/Stop" > manage extensions > disable Somnium
at "OpenXR" > OpenXR API Layers > disable Somnium
set SteamVR as default runtime, if the runtime is Somnium one
optional, but I would recommend to unplug the VR1 Headset from USB
Removal:
Uninstall the VR1 Tool (beta) via Control Panel > Apps
Restart PC (important to fully uninstall the running services)
Folders to delete (after the PC restart)
"C:\Program Files\SomniumSpace" (without space between Somnium Space)
"C:\ProgramData\vrg"
"C:\ProgramData\somnium"
"%appdata%\VRG" (which is equal to "C:\Users\AppData\Roaming\VRG)
"%localappdata%\Vrgineers_Inc" (which is equal to C:\Users\AppData\Local\Vrgineers_Inc)
Steam related folders (depending where you have installed Steam and your SteamApps)
"C:\Program Files (x86)\Steam\config\somnium"
"C:\Program Files (x86)\Steam\steamapps\common\SteamVR\drivers\somnium"
Next step, only do it, if you are familiar with JSON files
and you know what you are doing. Backup the file.
Open in an Editor the streamvr.vrsettings of
"C:\Program Files (x86)\Steam\config\steamvr.vrsettings" and delete the JSON object for:
   "driver_somnium" : {
      "enable" : true
   },
if exist, also remove
   "driver_vrg" : {
      "enable" : false
   },