You can't do it, and that sucks, but there are two solutions.

1. Press the E button twice during your performance of the song. This will give you the simple ending. Press E then D to change to the simple intro (especially good for breaks).

2. Copy and paste the style onto a floppy or into precious USER memory. Now you can choose the intro and ending of your choice and resave the style. Now when you recall this style, it will be set to your preferred intro and ending. While you're at it (See recent threads), you can save the style with your preferred tempo and OTSs too!

Larry