If you just want a change of style part way through a piece, then as Pino said, the best way is simply to use Registrations.
Two things to remember: 1) the tempo for both styles must match and 2) it's worth going into the Mixer and making sure that the Drum Kit and Bass sounds are the same for each style used. (Unless there's a good musical reason why 1 and/or 2 should not apply, of course!)