First you cut out the "book pages" with a cutter knife. The two strips with GLUE are to be glued together. It is best to use a glue stick for this.
Next, cut out the covers and sort them into the appropriate book pages. Now fold the edges. The paper is self-adhesive and is difficult to fold later without sticking together straight away.
Now you can remove the protective paper, glue the edges inwards and glue in the book pages.