Converting .oxps document files directly to Adobe .pdf format.
Converting Open XML Paper Specification .oxps document files directly to Adobe Portable Document Format (.oxps to .pdf conversion) can be easily accomplished using the virtual PDF printer function in Microsoft Windows 8 or later.
In that case:
If you are still using Windows XP (or older), you might need to look for third-party alternatives, even though your chances that some of them support the .oxps files type are pretty low.
Alternatively, try one of the numerous available conversion tools by searching oxps-to-pdf or oxps2pdf.
To convert oxps to pdf on MacOS, try to use XPS-to-PDF for Mac converter, capable of direct and batch oxps or xps to pdf conversion. XPSView is another tool for Mac for viewing .oxps or .xps documents, and then you can print it to .pdf and save it to a file.
A simple and efficient way to batch convert XPS or OXPS (OpenXPS) documents into PDF. The XPS-to-PDF supports JPEG, JPEG2000 and Flate image compression types along with output quality for PDF conversion.
One of the many document converters for Mac
An XPS/OXPS to PDF conversion services
An XPS/OXPS reader for Mac