You just need to download the disk image. Next double click on the disk image, and drag the enclosed ADF2007.01 directory somewhere on your hard disk, such as the Applications directory. Read the (Mac OS X Installation Manual) for more details.
When you double click on the 'ADF GUI' application in the ADF2007.01 directory it will check for a valid license. If none is found, it prepares an email with the information you need to send to SCM to obtain the proper license file.
After receiving your license file, copy it to the ADF2007.01 directory and name it license.txt. Note that the license file needs to be a plain text file (not RTF which is the default for TextEdit).
If you do not have a license for the ADF GUI you will need to run ADF from the command line. To run ADF from the command line, you need to set the environment variables as one needs for all UNIX versions.