Exporting .spo output files is definitely possibly possible in the original SPSS statistical system. However outside of that software it may be very complicated. The open source alternative (PSPP) does not support import of .spo files which is usually the very first software people without SPSS try. However you may download the SPSS Legacy Viewer that you can still download on some websites and use that to possibly print the data as .pdf documents.
Convert SPSS 15 and earlier output data to Adobe Portable document format.
We found one software available in the database for this conversion.
Multiplatform software - convert spo to pdf on any platform
A statistic and analytic software from IBM
Convert from spo file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.