I can't give you a definitive answer, but I can start you in the right direction.
1) Look in Youtube for various Korg "In The Studio" series Kronos videos, most of those filmed with Rich Formidoni are quite thorough, informative and easy to understand. I have learned a lot about tweaking patches in my TR and M50.
2) On your Korg, there is a Page button. That puts you into the "behind-the-scenes" parameters of your combi. There are several divisions within this which will allow you to change settings.
Mess around with it and learn what each thing does. You won't mess anything up, and if you do, just back out and change to another patch, and all the changes are wiped. However if you make a customization that you like and want to keep, then press the write button, and Yes to the Are-You-Sure? question.
Check this video and see what I am talking about at around 3:12
Hope this helps.
