Download the dmg file, double-click it and move HLAssign into the Applications folder.
If Mac OS does not allow you to run HLAssign, you need to manually allow it in System Preferences / Security and Privacy.
See here: https://web.archive.org/web/20190927161304/https://kb.wisc.edu/helpdesk/page.php?id=25443
Unpack the HLAssign.zip archive at a folder of your choice. Browse into the sub folder HLAssign and double-click the HLAssign executable.
If you get an error, e.g. dll is missing, please install the vcredist.exe which you will find in the same folder. The vcredist.exe installs all dependent libraries.
Instructions will follow soon.
A tutorial video will follow.