1. Make sure iPhoto is quit.
2. Unzip the package you downloaded from this website.
3. Go to your Applications folder, and Ctrl-Click the iPhoto application icon to show a floating menu. Click the “Get Info” menu item. Your iPhoto Info Window should look something like this:

   

4. Press the “Add…” button under the “Plug-ins” tree, and using the Finder popup, find where the unzipped contents of the package are. The unzipped package should have a name “Photon.iPhotoExporter”.
5. Make sure that the Photon plugin is included under the list shown in the image above.
6. Open iPhoto, test and please inform me of any issues.

Not-so-easy Way

1. Make sure iPhoto is quit.
2. Unzip the package downloaded from this site. The package should have a name called “Photon.iPhotoExporter”.
3. Go to your Applications folder and Ctrl-Click the iPhoto application icon. Select the “Show Package Contents” menu item. Doing so should open up a Finder window with a “Contents” folder inside it.
4. In this Finder window, go to Contents -> Plugins. If you find an old existing “Photon.iPhotoExporter” folder inside, move it to Trash, for you should be using a newer version.
5. Drop the just-extracted “Photon.iPhotoExporter” folder to the Plugins folder from the Finder window we opened earlier.
6. Open iPhoto, test and please inform me of any issues.

You could send questions through this blogpost’s comments section, forums, or email.