Step 1: What You Will Need
An A4 sheet of card
A pair of scissors, sharp enough to cut through the card
A sharp/mechanical pencil
Long, thin, tweezers
Possibly a stanley knife and cutting mat for the slits
Step 2: Printing, Cutting
When you have the print-out on card, carefully cut around the outside and the slits of faces 1, 2, 4 and 6. You could use a stanley knife for the slits.
Now, you see the line horizontal across face 5? Cut a 5mm slit along the middle of it, and another 5mm slit perpendicular to the one you just cut. Cut away the triangles to get a 0.25cm(^2) hole.
Then, place a small blob of blu-tac underneath the antenna of the green candy monster and poke your pencil end through it. Make sure this hole is big enough to fit the thread through. Then, bend the top of the antenna back a little (from below the rounded part, not the whole antenna).
Remember to cut out the hole on face 3, I shan't patronise you in how to do so.
Step 3: Constructing
You probably want your box to hang at a different length to others, so add the height you want it to hang (from the tree to the top of the box) to 2.5cm and double it. It's 2.5cm because the monster, from the bottom of the tab to the middle of the antenna (below the rounded part) is 31mm, which we take off the 56mm of the box' height to leave us with how much string will be needed to reach the top of the box. Then add however far you want it above the box and double it to create a loop.
Say the final length was 17cm of thread. Thread one end through the antenna hole and leave it for now - do not fasten off the other end.
Constructing the box from the net is simple enough, just fold on the lines and fit the labelled tab flaps into their tab holes. If you have particularly thick card, you may need to score the lines with your scissors. You may want to glue the tabs in, but I didn't.
Make sure you push the thread through tab hole G with the monster.
When the box is a box, pull the thread from inside through the hole in face 5 with the tweezers and level the ends delicately. Straighten them then, sitting the box on a flat surface, put two twists in the thread - twist one half around the other 360 degrees clockwise so it's back where it started, and then do the same with the other. These twists shouldn't come out when it spins, and try to keep them inside the box if you can. Then tie the ends of the thread together.
Then, wait until December to hang it - or place it, if you don't go for the bauble part.