As you can see in this point there will be gaps and to try to fill those gaps i used hot glue but you can use anything you like.
You are going to fill those gaps with the glue and try to make them as flat as you can so it is easier to paint.
Once the glue dries you are going to take the white paint or white out and you are going to paint only over the glue.
If it is white out give it one full day to dry because for some reason white out dries a lot quicker on paper than on hot glue.
If paint you can check every hour or so.