I just used otachan's ASIO-dll and copied it in the plugins-folder. After that I could just select that outplut-plugin in the options.
You can get the dll here: http://otachan.com/out_asio(dll
)_067.7z (you have to use 7zip or Winrar to extract that file)
By the way: Why so you want to use ASIO? The audio-quality isn't supperior the deley is just shorter which has no effect on the quality...