How to Change the Blade:- 

1. Place the circle cutter flat on a table ensuring the blade has been twisted away. 
2. Loosen the white positioner and gret retracter together and remove this part from the blade holder. 
3. Carefully twist the tube containing the blade to remove tube containing blade from the postitioner.
4. Revert the tube to tip out the old blade and inster new blade into the tube.
5. Carefully place the tube back into the positioner and twist to tighten. 
6. Place the white positioner back onto the clear base on the cutter and twist to tighten - you may need to ensure the grey plastic base underneath stays in the correct position.