How to replace Microsoft's SSD Driver into Intel's Rapid Storage Driver (iaStorAC)

Hi guys,

I installed Windows 8.1 on my HHD with SATA mode AHCI, And then I switched the SATA mode to RAID to use the mSATA SSD with Intel Rapid Storage Technology.The problem is that there is no option for Enabling Acceleration in Intel RST.

After a few searchs, I found the problem is driver of SSD is not Intel's F6 iaStorAC. It's Microsoft's Windows 8.1 driver.

I tried to use "update driver" feature of device manager to change the driver into Intel's iaStorAC, but Windows said something like "the driver it's new",

So my question is, how to change the driver without reinstall OS?