Hi
The following steps may help:
If your Apple Watch cannot be turned on or restarted normally, then it may help to force restart it:
Remove any case, bumper or screen protector that may be fitted to your Apple Watch.
Unpair and re-pair your Apple Watch:
If the password cannot be entered on the Apple Watch and/or it cannot be unpaired via the standard process, then it may be possible to erase it manually by following these steps:
- Connect your watch to its charging cable, connected to power.
- Whilst keeping your Apple Watch on the charger:
- Press and hold the side button until you see the Power Off slider.
- Press firmly on Power Off (do not try to slide it - just press down more firmly than a normal tap), release your finger, tap on Erase all content and settings and confirm when prompted.
- Re-pair your Apple Watch using the Watch app on your iPhone, choosing to Restore from Backup if offered the option.
- More information:
If the issue persists or you cannot follow any of those steps, then I suggest that you contact Apple Support (mail-in service may be available, if required), make a Genius Bar reservation or visit an Apple Authorised Service Provider for assistance: