First we will open the strap with deployant closure. This latch has a metal notch that hooks into a hole. We just have to do a bit of force to separate them. You can also pull the outer rubber out, so the piece itself will leverage and open.

To separate the strap from the Smartwatch we only have to press the clamping piece as shown in the photo. Once the piece is pressed, it will come out practically alone.

To remove the casing we must remove the 4 Torx screws that it has in the back part. Then we will leverage with the opening tool and it will open easily.

Once opened, in the case we will find the battery stuck. Before proceeding to remove it, it is better to take off the flex to avoid breaking it.

The battery has a sticker on which it says "Pull". We can use it to pull it or also carefully lever below the battery.

Clock battery, modern things ....