The prop shaft is fixed to a nut built into the body.
Remove counterclockwise and replace with a new prop set.
As you tighten the shaft, it hits the inner wall of the body. Tightening it any further may damage the body.
When replacing parts, the edges of parts and hooks are sharp, so please be careful when handling them.
** WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. **