You'll need to cut up some chopsticks and 10mm dowels to assemble the habaki and hilt respectively. Or, I guess you could just print some dowels yourself. You also need some glue and rough sandpaper.
If gluing isn't enough keep the sword together you can add dowel holes on each cut. That should help. In my case it was enough to use glue.
The author remixed this model.
With help from another 3d modeller, I was able to fix some bugs in the original model which messed with my printer.
I made the scabbard into one part so you can split it into the right height for your printer.
I made the scabbard a little shorter to save on plastic.
I remodeled the hilt to my liking, it's smaller now.
The aforementioned 3D modeller made the blade a shorter. The blade is ~ 66 cm now.
I did not touch the Tsuba, Habaki or Scabbard Cap.