You could put each drum on its own midi track and run it to a separate instance of the DXi. There is a Cal program that will split the notes out for you. It's called Split Notes to Tracks.
However, I prefer to do it manually, since I like to keep certain notes grouped together on one track, e.g., Open, Closed and Pedal Hi Hat. What I find fairly easy is to clone the drum track a few times, and then delete whichever drums I don't want from each track. You can select an entire drum sequence by clicking on the corresponding piano key. This will highlight the entire track for that particular note, then just hit the delete key.