How do I apply changed Instance Variable to each sprite.

I have a sprite. It has an Instance Variable.

This Instance Variable is "hit", and it is on a box.

It tells the game how many hits it takes to break the box. It's set to 3.

I placed all the boxes down, and now I've realized hitting the box 3 times is too much.

Now I have to go through and apply "2" to "hit" on every single box I've placed. Is there a way to apply the updated Variable on every single box with the press of a button? Thanks a lot in advance

On the right side in the objects-tab. Choose your Box-Sprite and make a right Click on it. Click on Instance Variables and then on Edit (the little pencil) and change your value. This should apply to all Instance-Variables of this Object.