I want to transfer my Apple Watch to a different phone how do I do that

Make sure you unpair it first.

from the watch app on your iPhone, open the app. On very top left corner you will find; (Watches)... click the word that says watches on the very top left corner. Then select the watch and unpair it.

then do this with the other phone... This link might help... 👉🏼 https://support.apple.com/en-us/HT204505

if it’s going to be a different Apple ID, make sure to remove it from your account/iCloud.

See > How to pair your Apple Watch with a new iPhone - Apple Support