You just need to move the Country Waltz over to the USER area on your keyboard. Then you can DELETE some of the Style parts to make it less busy. Then you need to save it to a USB stick with a new name. You can also copy the drum parts in the MAIN A and then paste them into MAINs B,C and D to also make it less busy.
I was in fact making a custom song style for the Kenny Rogers tune, "Lucille", just today. I was running into the same issue, too MUCH going on the style. I Delete all the PAD, PHR1 and PHR2 parts in all the parts of the style.
Regards
Drake