If styles have a different extension than .sty you can just change it to .sty. But not all styles sound correct as not all voices are available on each model keyboard. With a bit of luck you will hear a substitute voice or you don't hear it at all.
If the styles are SSF2 and you need SSF1 you can download from this forum (Jososoft) a program made by our great guru Jorgen to convert it.
Hope this helps.