If you want to edit a drum kit here's how. First go to that kit and press edit, which puts you in edit mode. Next press Global, then press P5 which will take you to the drum kit edit screen, all programming and tweaking of the drum kits are done from this screen. Towards the top left, there is a key assign, which shows you what key you are curently programming ( it will also show you on the keyboard display in the screen .
How you want the individual sound to sound depends on how you program it. Each key can have either 1 sound or 2 sounds, that can also be split by velocitey. If you only put one sound on a key make sure you set the "bottem velocity" in the lower left corner to 1.
So here's an esay way to do it. Pick stadard kit press edit, press global, press P5. Next pick which key you wish to edit. Keep either the high or the low sound ( turn the other off ) turn "bottom velocity" to 1. Next high light the sample which you have kept, and scroll thru the drum samples available either by the dial, buttons etc... then just mess with "Tune / Level / decay " to tweak the sounds. It will take a little getting used to, and I'm sure not the greatest at directions, hope this helps though.