how do I operated your pvc pipe cutter C0230?

Related Questions

PVC pipe cutter C0230 - where is this product actually made? I can't see any indication on the tool itself or on the packaging.
I have just bought an Amtech 42mm plastic pipe cutter and cannot use it. Can you tell me how to release the blade to cut as I have tried and can't seem to get it to work.
How do you change the blade in the pipe cutter?