Enter the passcode on the Apple Watch
Unlock the paired iPhone, then wear the watch and keep the iPhone nearby
Turn on Wrist Detection in the Watch app on iPhone
If the watch is locked because of too many passcode attempts, wait and try again
If you forgot the passcode, erase the Apple Watch and set it up again
On Apple Watch, go to Settings, then General, then Reset, then Erase All Content and Settings
On iPhone, open the Watch app, then General, then Reset, then Erase Apple Watch Content and Settings
If Activation Lock appears after erasing, sign in with the Apple ID used to set up the watch
If the watch is managed by an organization, contact the administrator to unlock it