I don't think you can change the actual intro/ending from one style for another, you can however change the drum set used for into/ending/fill ins and variations etc. and other things like bass sound, chords......
I've just taken the Hard Rock style, swapped all the drums to the Rock set and then changed the rhythm1 to the cool8beat drum sounds which completely alters the style.
It know has more of a ballsy feel to it with lovely sort of bongo sounds coming in lmao - Sound funny typing but it's ideal for Summer of 69. I've also changed the guitar sound on the intro and ending to the distortion one, a damn site better. I'll send it you lot on Skype after tea. I'm in tweaking heaven again so I may be gone for some time hehe