Unzip the file. It contains three files: EREntityToHTML-x.x.x.jar, index.css, and entity.css.
Drag the .jar file to an open instance of Astah. A pop-up will appear asking you to confirm installation. Choose [Yes], then restart Astah.
If you see [Px3Tool] under [Tools], the installation is complete.
How to Use
Open the file that contains the ER models you want to export to HTML.
Go to [Tools] – [Px3Tool] – [EREntityToHTML].
A pop-up appears when the HTML export is complete.
To apply the style sheets, save index.css and entity.css in the same folder as index.html.
Samples
Exporting the ER model above (from sample.asta in the Astah installation folder) produces the pages below: the entity list on the left and the Customer entity on the right.