You can buy the conversion software, or you can probably find the styles already converted at PSR Styles Group.
But, a word of advice--give the Yamaha styles a chance before you start converting.
Very often, when we get a new keyboard, we miss certain features or styles that we had before. I feel this is usually because we are accustomed to hearing them. We buy a new keyboard, and immediately start trying to make it sound like the one we replaced.
I have been guilty of this many times.
Play with the new one awhile, and fully explore all the preset styles and the Yamaha styles available freely on the internet. (Particularly the CVP styles.)
Then, if you still feel you need a few from the Roland, do it. You may be surprised to find you don't want them. Converted styles rarely sound as good on a different brand keyboard anyway.
Good Luck and enjoy the 9000.