Yamaha DTX900 as external instrument

In theory I think I should be able to set up my Yamaha DTX900 drum kit as an external instrument in Cubase pro 8.5 and record midi/audio tracks combined - with separate tracks of kick, snare, stereo toms etc

Trouble is I can’t make any sense of any instructions I have found on how to get this working correctly.

Has anybody ever done this?

Anyone ever found a youtube video or similar walk through of the issues involved?