How do I return my Apple Watch to factory settings to return the watch

This link will walk you through the steps: Unpair your Apple Watch and iPhone - Apple Support

There is a process to erase and restore - or leave at a state where it would be

as new for someone else to set up with their AppleID - and sync with iPhone.

The topic of erase all settings and the basics are covered in these links:

• If you forgot your Apple Watch passcode - Apple Support

• Set up your Apple Watch - Apple Support

There may be additional resources for the Watch in Apple.com sales & support pages.

Another general resource that requires a little reading to find specific topics:

• Apple Watch User Guide:

http://help.apple.com/watch/

{Sprinkled within other topics several of the blue text links offer erase advice

that usually also has how to restore after. ~ Be sure your activation lock is off

& unpair when getting rid of a device; then it won't be associated w/ Apple ID.

There are at least 15 or so links within other articles that go to same pages.}

This community is for iPhone users.

Please address your request to Apple Watch Support Community, here: Apple Watch

Regards

Giulio

Because Apple watch users, by and large, also have an iPhone

and need to at some time or another use both including to reset.

{That is why this thread is exactly where it belongs.

iCould have asked the Hosts to simply relocate.}

Checking one search result suggests most would have you use iPhone with Watch:

https://duckduckgo.com/?q=how+to+reset+Apple+Watch+to+factory+setting+without+iPhone&t=ffsb&ia=web

If you have an iPhone, that should ease the means available to you

to erase the Apple Watch and disassociate it from your Apple ID.

By several measures: Q: ..topic of this thread has several workable.. A:

In any event...

Good luck! 🙂