The answer is simple donny. Use the other functions of your arranger . it has other button on it than start and stop play :-)
You know i am only teasing you Donny. Try some of the editing functions on your instrument and be amazed.
You know, Spalding, many people use less than 75% of their arranger, and to some it is mainly a SMF player to sing over, not that there's anything wrong with that.
The sound editing functions on the PSR-S910/Tyros4 are fairly extensive, and the Korg arrangers have even more capabilities.
For most, basic editing is fine; in fact very few use it, but, you can do a lot even with basic editing.
Same for styles...most people do not program from scratch, but edit an existing style, either by re-voicing or swapping parts in from another style. I teach style editing at my followup clinics...it's actually quite easy, as is sound editing.
Ian