Older versions of the SI4735-D60-EVB were offered by Silicon Labs. This product was later divested to Skyworks Solutions, which has dispensed with the installation CDs seen in older images of the product. Without any installation media, how do you get the software the kit relies on?
In this case, the software can be requested directly from Skyworks, here: Skyworks | Contact Sales. You can also have us request this software for you once the board has been purchased. Unfortunately the software does not come bundled with the board anymore since the divestiture to Skyworks, and must be requested separately post-purchase.