I just purchased a ZONA mini hack saw for some scenery demolition and rebuild. The handle came with a fine tooth blade, so I also purchased a package of course tooth blades. My question is, how I can change out the blade, short of punching the pin out, and replacing the pin after the new blade is in place. No instructions came with either package so I went to the web site, but no joy. Do I need to clamp the bugger in a vise? Any tips or hints would be appreciated.