Papercraft here: http://pixelpapercraft.com/papercraft/53298ae8a7d7...
You will need:
Step 1: Cut Out the Pieces
Step 2: Create the Spool
Pieces: 5,9, and 6.
First wrap 5 around 6. Then glue 5 in a cylinder shape that can fit around 6 and fold the flaps OUT. Then make sure the rings(9) fit around 6 as well. You will probably need to make the holes bigger. When you are done with that glue two rings back to back and glue them to 6. Do the same thing with the other rings on the other side.
Step 3: Finish the Spool
Pieces: 5,9,6, and 8.
Put 6 in the spool(5,9) and make sure the spool can spin around it. Now fold 8 in half (and glue it). Next glue 8 to the top and bottom of 6. Then glue the string to the spool. When that dries wrap the string around the spool.
Step 4: Make the Body of the Gun
Pieces: 3,4,7, and the Itty Bitty Piece.
Fold 3 in half and glue it (DO NOT GLUE THE LITTLE CUT OUT BITS). Then take the 4s and fold them into triangles, and glue them to 3. Next make 7 (turn it into a box, I hope you know how to do this) and glue it to 3 right behind one of the 4s (the side you put it on decides what hand your mini will hold it in). Then take the itty bitty piece and fold it in half and glue it. Then curve it so it makes an arch and glue it to 7.
Step 5: Attach the Spool
Thread the string through the itty bitty piece and then glue the spool to 3. Then make the 2s and attach them to the little cut out bits.
Step 6: Make the Hook
Fold 1 like in the picture and glue the string inside. Then trim the string.