From what I see,
You have a couple of choices:
Both options require that the SSD be removed from its current role. This entails going into the Intel RST OpROM by pressing CTRL-I during BIOS startup and marking the SSD as not in the array any longer.
If you decide to add another SSD and use it as a cache as you were previously, add the SSD, boot into Windows, run the Intel RST program and then set up the Intel SRT caching as you did previously.
Hope this helps,