And hit jobs at the top, search for series 2152. PUBNAT7 is the most recent application and should appear at the top, this is the application for you if you are applying off-the-street with no previous ATC experience or if you are not a CTI grad. Click PUBNAT7. On that page about halfway down you will see a link to the FAA's ASAP page, make an account there, fill out the required fields, and hit submit application.
And then you wait. The FAA will clear you to take to test and will send your name to the test contractor, who will then contact you to schedule the test.