- If you haven't downloaded Photomatix Pro yet, please do so from the download page.
- If a Lightroom installation is detected on your computer, the installer will ask to confirm that you want to install the plugin. Make sure the box "Yes, install the Lightroom Plug-in too" is checked before clicking "Next".
- Restart Lightroom
- In Lightroom, select bracketed photos from either the Filmstrip or the Grid.
- Right-click on the selected photos to invoke the contextual menu. Select Export and then Photomatix Pro.
Important note: If you have checked the "Automatically re-import into Lightroom library" box, click above the filmstrip to check that "All Photographs" is selected. In case "Previous Import" shows, then click on it and select All Photographs instead.
See also this short tutorial on the Export to Photomatix Pro Plugin for Lightroom.