.... while reducing the size from 32GB to around 15GB?

Background: The server has the pool SYS containing volume
SYS (besides other pools and volumes) placed on one disk.
Due to a disk-hardware-problem the disk containing SYS (pool
and volume) has to be replaced. While so far SYS (pool and
volume) had 32GB (which are not needed) the size shall be
reduced on the new disk.

I first thought of mirroring, but that will not let me
reduce the size. Second idea was the VCU with TID 10088251,
but that still looks a bit frightening to me (I have done
this on a test-server some years ago and that was quite a
hard thing). Are there any other cool ideas on how to rescue
the server?