1 Go to "SETTINGS » LAYOUT » ACTIVE THEME » MODULES"
2 Click in the "Add a module"
3 Enter "The Title" and possibly select to module was bounded (this is not required)
4 Click in the "Close Editor" on the toolbar,
5 Paste the script and click "Save"
NOTE: To avoid cutting out HTML codes you might want to select the "Disable HTML code cleaning" to do this go to "SETTINGS » ADMINISTRATION SYSTEM