I have had the same problem! I have been searching the internet for the manual so far with out sucess. However I went back to the saw and was able to install a new blade. This is how:
1. Slide the button on top of the saw out, forward away from the body of the saw.
2. Rotate the button anti-clockwise - unscrew it. The jaws open and the remains of the old blade will come out.
3. Insert new blade and rotate the button clockwise to close the jaws and clamp the blade.
The saw is now ready for use.
Keith Rowe, December 2006