Remove an HDD from a RAID 6 Array

[CPA-UK]

I've had a bit of an accident adding a new HDD ro my Array on my Smart Array P420i

I had 5 x 600GB SAS drives setup in a single RAID 6 array....

My plan was to add a further two 600GB drives, one to extend the Array and one to be a HotSwap spare...

Somehow I have managed to add both drives to my Array and it is now showing as 3.8TB online..., so at least it is working but not what I wanted... (see attached JPG)

Is it possible to remove the last HDD, and move to to the HotSwap spare..?

Thanks in advance..