So you want to change the drawable image of your CheckBox widget but when you compile the app, the image and the text are almost side by side.
I bet you used the attribute android:button in order to do this. This is the culprit. To change the CheckBox image with your own custom images, use the attribute android:drawableLeft.
But wait! Now, there are 2 CheckBox widget images!
Here is the complete XML code to use your custom CheckBox images as well as increasing the space between the icon and the text.