Most of the holes on this thing are self threading meaning you take a m3 bolt and screw it in to stay inside. If hole are not self threading there's either a reason or you are supposed to take a m3 bolt and nut it from behind. You glue the whole thing together with super glue or weld-on. Assembly is straight forward. Do not put any glue on the top piece because you need to access the inside of this somehow if needed. Enjoy!
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