Mario...
It's been awhile since I have done it, but a quick review of the manual (Pg 62) reminded me that it is done through the Style Manager.

1. Insert floppy with the styles you want to load into the 9000
2. Call up any internal style from the style keypads on the left side of the screen.
3. At the bottom, open File Manager.
4. Hit A-1 "Load Style Into Flash Rom"
5. Here you will see a screen that shows all the styles on your floppy. Scroll to one you want to load.
6. Press "NEXT".
7. Select which Flash Rom number you want to load the style in. (Be sure to pick one that contains similar genre)
8. Scroll down the styles in the selected Flash Rom number until you see "NO DATA".
9. Press "NEXT".
10. At this point it asks if you want to load the style to that slot. Press "YES".

I just tried it and it worked fine. Hope that helps you.
Eddie