Can you replace a swollen battery in my Apple Watch?

Yes, It can be fixed! Given the fact the screen is already pulled away a bit it should make doing this your self much easier. Are you up to it?

To help you, review this vid of Alex opening a Series 2, it's the same for your Series 1 (the Original Apple Watch is a bit different) How to Replace the Battery on an Apple Watch Series 2 and you might want to review the Original Apple Watch guides while slightly different the same techniques are needed: 更换苹果手表的电池 I'm sure you can forgo the iOpener as the display is already lifted. You will need to fully clean the surfaces of the old gasket both the case and the display. And do be gentle! The parts can be easily damaged.

Here's the needed parts:

• Apple Watch (38 mm Series 2) Battery
• Apple Watch (38 mm Series 2 & Series 3 Cellular) Force Touch Sensor Adhesive Gasket

• Apple Watch (42 mm Series 2) Battery
• Apple Watch (42 mm Series 2 & Series 3 Cellular) Force Touch Sensor Adhesive Gasket

Just take your time and don't forget to breathe ;-}