I'm in the process of trying to change the KeySpec property of a code signing certificate from Comodo by following this guide. The guide mentions importing your certificate file into MMC and then exporting it again later. However, I don't seem to have the option to export as a PFX file. I already have a PFX file; I can import it successfully, but when I go to export the option is greyed out / disabled.
What do I need to do to enable this export option?