I don't think you can get them for free. I use http://www.dressagediagrams.org Each test cost £1.50 and you get the diagram and the written sheet avalible there and then for you to print off as many times as you like
you can't get them for free because of the copyright, but if you sign up to dressage diagrams and pay about 50p you will see the test in diagrams on your screen almost immediately, and for £1.50 they will send the official test sheet in the post - they're really quick.