You execute the tests by using Ant. You could equally run them manually using the process described in the overview section but running them via Ant gives you several advantages, not least of which is the ability to run them automatically and as part of a build process.
This infers that the templates should be tested as part of a build process, if
they form part of an existing project (say that has Java in it), you may already
be using Ant to perform builds. If not, you will need to create a
file to run.
See the Ant Reference section for more details about creating an build file that using the Ant task.