remove drive from array and assign as hot spare

We have a CT-SC8000 SAN. We are utilizing the SAN as secondary storage since our warranty ran out and we did not re-up on support. We had a failed drive and the SAN consumed the spare we had in that enclosure. I now want to remove another disk (shrinking the RAID) to assign as a spare since we will not be purchasing hardware for this SAN. Do I just release a disk, rebalance and then the SAN will recognize the released disk and assign as a spare? Is there another way of doing this?