To assemble, download and print the files above. For the button, print 2 copies of them. Take your 22mm (classic skateboard bearings) and align them with the holes. I recommend using a small hammer to gently hit the bearings in the holes (the fit should be tight). Finally, take the 2 button copies and slide them through the hole (on both sides) on the middle bearing. Same as bearings, you may need to apply lots of force or gently tap them with a hammer.