change style in imported midi file and save

[bassgolf]

Greetings from Canada,

How do I assign a Tyros 5 style (mainly drum track) to an imported midi file that I created in Sibelius and then save that file with that style so that the next time I open that midi file on my Tyros 5 it uses that style? It seems every time I try to change a style it uses whatever style I had lastly used.

Regards,

bassgolf