Software Update Error Apple Watch. If asked for your iPhone passcode or Apple Watch passcode enter it. If you have an original Apple Watch Series 0 Apple Watch Series 1 or Apple Watch Series 2 you cant update to watchOS 7.
Keep Apple watch connected to charger. Apple Watch is on its charger and has at least a 50 percent charge. This will remove the WatchOS software update.
Go back to the main Settings screen tap Bluetooth then turn off Bluetooth.
Now you know how to update Apple Watch properly still you cant do it. After that on your iPhone open the Apple Watch app tap the My Watch tab then tap General Software Update. Click Delete again to confirm. From the Watch app click on General Software Update to re-download the update.