What's your platform?
Adding the code snippet to your wordpress is very easy. You can actually do this in so many different ways. For the sake of convenience, we shall use a plugin.
Head over to the wordpress dashboard, and click on plugins in the dashboard menu
Search for a plugin called "Head and Footer Code" by Aleksandar (Image below)
Once you've installed this plugin, hover your mouse on "Tools" (on the wordpress dashboard) and click on "Head and Footer Code"
Final step will be to place the code snippet from VoiceMondo into the "FOOTER code" section box and click save.
Once you paste the code snippet on there and click save, you should be all set. Someone times certain plugins running high loads of javascript might be affected, however, when this happens, try pasting the code snippet in the "HEADER code" section and reduce the priority scale from 10 to 1
All you have to do for this is to paste the code before the closing body tag.