If your Apple Watch firmware fails, the only way to fix it would be to send it to an Apple store. This is because only the Apple Store or authorized repair centers will be able to properly access the smartwatch’s data port, which regular users cannot.
This means that restoring firmware on an Apple Watch is not as easy as on the iPhone or iPad. However, there is good news because in the latest iOS 15.4 update, it looks like Apple will now allow iPhone users to rollback Apple Watch firmware, saving them the hassle of going to the store and to save time.
This will require users to have the latest updates on their iPhone and Apple Watch, which right now is iOS 15.4 and watchOS 8.5, so as long as you have those two updates, you should be able to roll back the firmware to your Apple Watch. through the iPhone without any problems.
If you’re interested in how to do it or maybe you want to bookmark it for later, Apple has published a support document on its website which you can refer to for more details and troubleshooting.
Deposit 9to5mac. Learn more about Apple Watch, iOS, Ios 15, iPhone, Smartwatch and Wearable Tech. Source: