You don't need to change anything but the wiring. I did mine on my '06 and it did require longer throttle, clutch and brake lines, but I wanted stainless steel lines anyways, so I did them at this time. I didn't need to change the risers and speedo, though I could see how it could look better with different risers.
Here is a pic of my '06 XL1200C with mini-apes:
