how to backup apple watch and reload to different apple watch
instructions to backup apple watch 4 and restore to new apple watch
Apple Watch SE, watchOS 7
Question marked as
Unpair the Watch from your iPhone. While it is unpairing it will create a backup of the watch.
Then set up your new Watch, during set up you will be given the option to set up the new watch with a backup.
Unpair & erase an Watch -
https://support.apple.com/en-us/HT204568
Set up your Watch -
https://support.apple.com/en-us/HT204505
M1 Mac mini, macOS 11.1; Watch, series 5 GPS/cellular, watchOS 7.3.3; iPad Pro 2nd Gen, iPadOS 14.4.2; iPad Air 2, iPadOS 14.4.2; iPhone 12 Pro, iOS 14.4.2; TV 4th Gen, tvOS 14.3 HomePods, audioOS 14.3 and Airport Express w/ Airplay 2