Make sure your server where LiveAgent is going to be hosted (installed) meets the minimum requirements:
Download your ordered package from https://members.qualityunit.com/customer/ and remember the license ID. Upload the package (ZIP file) to your server if you can unzip it directly there, if not, then you have to unzip it in your computer first and then upload all files to the server.
Set directory accounts/ to CHMOD 777 so the installer can populate all the needed files to that directory. Before installation you should know that you will need MySQL database info where LiveAgent will be installed to. (make sure the collation of the database you are about to use is set to utf8_general_ci, otherwise you will run into problems)
Run installation - if you uploaded LiveAgent to directory /liveagent/ then the URL of installer is http://www.yoursite.com/liveagent/install/
Step 4 - Installation
The installation is very simple. In the first step you have to choose a language of the installation. The language will be used for setting the application language as well. You can import multiple languages for your agents later.
After choosing a language you will be presented with a welcome screen which checks your server configuration and whether it meets the requirements.
After checking the requirements you have to define your database details to be able to install your new LiveAgent.
Now you are connected and you have to enter your LiveAgent license ID that can be found in members area ( https://members.qualityunit.com/customer/ ) and agree with license.
After validating the license ID you need to enter your owner (administrator) information.
When the account is created you will be asked to set up the cron job on your server. Cron job is required for the application to run correctly and therefore this step can't be skipped. The application needs to register the first cron job call and then it will let you through when you click on 'Next' button. So for example if you set cron to run every 5 minutes, then you will most probably need to wait for 5 minutes before you will be able to continue to next step.
Please notice that the cron job command consists of multiple parts like INTERVAL + PATH_TO_PHP and PATH_TO_LA. In most cases the problem is with the PATH_TO_PHP part and usually it works when you replace /usr/bin/php part of the command with only php. If that doesn't help then you can follow this guide or ask your server admin / hosting provider support for help.
Finally, you are just one step before you can start using your new LiveAgent. The last step is to set up your mail account which is used for fetching emails, sending out emails to customers, email notifications, reset password requests and chat transcripts.
If everything is correct you will get this window as the last one:
The installation has been successfully done... but as you know, this is not the end, this is just a beginning :)