It is normally not possible to change the style within a song. However, you are in luck, for there is a special style for latin/swing in the jazz style pack. It is called "latin/swing". I think it automatically reads the A in latin and the B in swing, but only in the first and last chorus (that is to say for the theme, the chorus being played in a swing feel on both A and B). Be careful to use the little A and B in your chart so that the player can read it correctly!

Best,

Naellita