You can easily convert Mac OLM files using MacUncle OLM Converter. The tool supports Mac OS Machines.
Download and Start MacUncle OLM Converter.
Upload the OLM file using Add File(s) or Add Folder(s).
Select File Format from Select Saving Option as per the requirement.
Choose Location to store file from Select Destination Location.
Press the Export button to start the OLM file conversion.