After the download is complete, drag the downloaded .jar file to an open instance of Astah. A pop-up will appear asking you to confirm installation, choose [Yes]. Restart Astah.
If you see the [Import FreeMind Files] option under [Tools] – [Mindmap], installation is complete!
How to Use
Go to [Tools] – [Mindmap] – [Import FreeMind Files] and select your .mm files (you can import multiple .mm files at once).
FreeMind map will be imported as an Astah Mind Map. All the hyperlinks will be imported also.