That can all be found by asking Google the same question. There's a bamboo shoot crosspin holding the handle on. Tap it out ans it all slides off...
Printable View
If you do attempt to remove the handle remember the 1st safety rule when handling these swords, always have the point of the sword toward the ground no matter what, that esp. includes removing it and putting it back in the scabbard, if the point is pointing up and you drop it, it is natural to grab it to prevent damage to the sword. even though these swords are very old, they can still be as sharp as a razor and with the handle on are very heavy, and trying to stop the sword from sliding through your hand by tighten your grip is not a good idea, esp. when lubricated by your body fluids.
Just a thought. ;)
I had that very thing happen in about 1976. I had a Japanese Navy Katana in the barracks and was showing it to my peers from the other companies. One clod about dropped it, bare blade and caught it by the blade. He cut the pad of his index finger, right next to the hand about as deep as possible without severing...off to the medics for stitches...I can even remember his name. By the way, the sword wasn't the least remorseful.
Matter of fact, if you can clamp the blade in a leather protected affair before starting stripping, you'll be magic...that will hold it secure.
That blade looks really rough - but it maybe the pictures. Are those scratches or actual flaws, cracks for lack of a better term. If they are cracks the value drops pretty dramatically.