Take two halves of the top of the lightsaber and glue them together like shown above using superglue. Leave glue to set.
Now take this part and glue it to the middle part of the saber like shown above. Use Hot glue or epoxy. Leave for glue to set.
Next take the bottom of the saber and glue it to the other side of the sabers body like shown above. Use Epoxy or hot glue. Leave for glue to set.
Lastly attach two buttons to the holes in the main body using epoxy or hot glue as seen in the above GIF. Leave for glue to set.
Your Shaak Ti / Adi Gallia Lightsaber is now complete. Hope you like it.