Remove old label holders or adhesive signs from the face of the shelf. Thoroughly remove any remaining adhesive with a citrus based cleaner or rubbing alcohol, such as mentholated spirits.
Ensure the opening edge of the holder is facing upwards.
Apply the holder from right to left, positioning the bottom of the holder at the bottom of the shelf face. No part of the holder should be below or above the shelf face however, if your holder is larger than your shelf face then the overhang should be at the bottom.
Once positioned, firmly press along the full length of the holder with a cloth to ensure a good bond to the shelf face.
Lastly, Insert your labels where needed through the top opening.