Get your supplies.
Cut the flaps off of the box and put them to the side for later.
Draw a triangle starting 19cm up from the base of the box and 9cm to the side from the top. Repeat on both sides.
Cut down the lines on either side.
Using the previously set aside box flaps, cut six (6) identical 9cm x 27cm inserts and two (2) identical 17.5cm x 27cm inserts.
Fold 1cm of each insert on either side. They should now all have a length of 25cm (i.e. 27cm - 2cm)
Using masking tape, assemble these pieces together two by two to strengthen each shelf. Tape together so that 1cm folds face downwards.
Glue the first shelf 13cm from the top of the box. Use hot glue directly on the box, as well as on the 1cm folds. Glue the next shelf 13cm down from the first. Repeat for the third shelf.
Glue the bottom shelf 5.5cm from the base of the box, then add a piece of cardboard between the bottom shelf and the base.
Cut a large 155cm x 25cm sheet of wrapping paper. Using scotch tape, tape the end of the wrapping paper to the back of the box.
Using the hot glue gun, continue sticking the wrapping paper to the shelving unit.
Cut out four (4) pieces of wrapping paper to cover the sides of the box.
On two (2) of the four sheets, cut out 9.5cm slats every 13cm.
Using your glue gun, glue them to the box.
Add masking tape where the unit isn't covered.
And you're done!