On inside cover of book, center tape over repaired area. Let the edge of tape over contents page come into contact at the outer edge. Using the bone folder, slowly smooth tape toward inside fold. Smooth tape into and over fold onto cover of book. These cuts should align with the fold of the cover.
Lower book spine onto tape, being sure it is centered.
Open cover and contents away from the cover which is lying flat on the work surface so that the inside of the cover is exposed. Fold the corresponding strip of tape over and onto the inside back cover. Using a bone folder, smooth onto cover surface. Fold the other end of tape to the inside in the same manner. I have had a few books that had such a small space between back cover and contents it was to insert the center flaps inside.