Open Settings
Tap Advanced features
Tap Side key
Set Press and hold to Wake Bixby to Power off menu
Go back to Settings
Tap Apps
Tap Bixby Voice or Bixby-related apps
Tap Disable if available
Tap Uninstall updates if needed
Open Bixby
Tap the menu or Settings icon
Turn off Bixby Voice, Bixby Home, and Bixby routines if available
Remove Bixby from the Home screen if present
Disable Bixby key shortcuts if your device has them