You can convert OLM to ICS without installing Outlook by using a specialized OLM conversion tool. Since OLM files store emails, contacts, and calendar events together, accessing them manually without Outlook can be difficult. Tools like the SysInfo OLM Converter allow users to add the OLM file, view calendar entries, and export them to ICS format. This approach helps maintain event information such as start time, end time, and reminders during the conversion process.