Sign up at press9 to generate your server token and a/b test code
and install the press9 a/b testing Joomla! plugin

Within your press9 home page, click Create A Test. Enter the URL of the page you wish to a/b test and click Go.
Change HTML, CSS, or add custom javascript.
Click Next when you're finished.

Access the Joomla! plugin by going to Extensions, then Mangage Plugins and find Content- Press9 A/B Testing.
Copy & paste the generated javascript from the previous step.
Copy & paste the goal javascript from the guide page, and replace GROUP-TOKEN and TEST-TOKEN with the values on the top of the guide.

Results from the test will start streaming in real time. Log into press9 to view results and calibrate statistical variables.