Convert PPSM to PPTM

The most convenient way how to convert ppms to pptm, i.e. PowerPoint macro-enabled slide show file (.ppsm) to a macro-enabled PowerPoint presentation (.pptm) would be to use PowerPoint itself. The very same ppsm to pptm conversion is also doable with any presentation software that supports PowerPoint formats, but for maximum compatibility it's always better to use the original software.