If you want to find out on your keyboard what notes there are in every channel,
I hope this will help you:
First find which of the 16 channels play the drum you want to change.
For drums usually is the channel 10.
To find out easilly, mute all channels and then unmute them one by one untill you listen the channel you are looking for.
After that go to Song Creator.
On my psr there is a tab there called "1-16" which contains all the informations for each channel of the midi like volume,duration of the notes some other things that very few can understand etc.
There must be something similar on your Genos.
Navigate down one by one the lines there and in some point you will see some notes name like C,Gb,F# etc and you can hera them if you navigate one by one as I said.
For example C is the snare and F# is the Tom for that particular drum set.
So you can find which note's volume you have to change.
Next to the notes symbols are the volume for each note.
It will take you some time to change all the volumes in Song Creator for a midi file.
If it is a style it is a lot easier to do it on the keyboard because there are few notes to change.
So Jorgen's program will help you save time.