Click "Run" when prompted to install the client. If not prompted, double click on the .exe file from your downloads folder or from the bottom status bar of the browser.
If prompted by windows security, click "Allow" or "Run Anyway" to allow the installation to proceed.
Follow the onscreen instruction to continue the installation. Make sure that the check box to run "Securus Video Runtime Environment" is checked and click Finish.
Open the downloaded macosx-securus-vre-install.pkg file from your Mac downloads folder or from the bottom status bar of the browser.
Follow the onscreen instruction and click "Continue" to start the install process. When prompted for terms and conditions, click "Agree" and then click on the "Install button". You may now be prompted to enter your mac password to install the client.
Finally, click on logout (if prompted) to finish the installation. Your system will be ready for video sessions after you log out and log back in.