you cant really..its a brass instrument thing..since they tongue like, at the back of thier teeth..they tongue on the roof of theyre mouth with the back part of their tongue and then a normal tongue...like saying " tada!! "

I've heard that Prof. Sinta's students are expected to master this technique by the end of their freshman year of study at Michigan, so it is possible, with a little incentive. It's basically saying TaKaTaKa or DuGuDuGu (try both). Begin on repeated notes, as an example, quarter note, then TaKaTaKa and repeat. Then, move up the scale in like fashion. The challenge is to make your Ka sound as close as possible to your Ta, which is hard since Ta is on the reed, and Ka is on the roof of your mouth with the center/rear of your arched tongue. It is possible, in theory, to literally double your tonguing speed using this technique. I believe that Prof. Sinta is reputed to be able to double-tongue 16ths at quarter=300, which I believe, as I've heard him play Czardis live and it was remarkable. Hope that helps--good luck!

Forgot to mention that Rudy Wiedoft was an early master of this technique, as well as triple-tongue (takata-takata-takata). Check out some of his reissued recordings...and prepare to be amazed by his mastery of technique and articulation, even if you feel that the music is not substantive.