1. Download one of the dmg files
2. Double-click the downloaded dmg file to mount it (Safari and some other
browsers may automatically mount the dmg for you after download)
3. In the mounted volume, double-click NeatImageSL.Intel.pkg (or NeatImageSL.PowerPC.pkg)
to start the installer and then follow the wizard to complete the installation
You may be prompted to enter Name / Password of the OSX administrator account
to install the software.