The first step is to enter the Clash of Clans game interface, as shown in the picture;
Click below to select the double-barreled cannon to be upgraded, as shown in the picture;
Click on the double-barreled cannon and then continue to click on the upgrade button, as shown in the picture;
After confirming the upgrade of the double-barreled cannon, click the upgrade button as shown in the picture;
In this way we can see that the double-barreled cannon has begun to be upgraded, as shown in the picture;
After the upgrade time is over, you can see that the double-barreled cannon has been successfully upgraded, as shown in the picture;
