After you click the orange "Download" button on the top right of the page, the .Zip file will automatically download. You will then need to unzip and extract the .PDO files from the .Zip file. To unzip a file on a Windows computer, right-click on the zipped file, then select "Extract All" from the menu, choose a location to save the extracted files, and click "Extract." Once you have done that you will want to open the the
halo-3-mjolnir-mkvi-cqb-chest-left-hand.pdo or halo-3-mjolnir-mkvi-cqb-chest-right-hand.pdo in Pepakura depending on which side you want the knife on.
I saw you also mention 3D print, you can find the Halo CQB chest in a list of free 3D print files here:
3D printers are rapidly becoming a prop and costume builders best friend and many of the members of the 405th are extremely talented at developing high definition and accurate models for printing. This thread is an index to help both new builders find quality models and showcase the hard work of...
www.405th.com