Can I release an ASM "disk" "on-the-fly"?

All:

We are in the process of migrating from an old EMC storage Array to a new EMC storage Array.  We use ASM.  The Oracle DBAs will be migrating from old disk volumes to new disk volumes using ASM "add/delete" in some cases and creating Clones in other cases.  (I'm a Storage Administrator.)  They now tell me that they need an outage on the server for ALL of the ASM instance to "release" the old disks; i.e. - they need to stop the ASM process.  We can have multiple (1 -5) ASM SIDs on the same server or cluster (with CRS), and they will be migrating the SIDs one at a time.  I asked them if they could "release" an old ASM device "on-the-fly" so that I could reclaim it from the OS (HP-UX 11.23), and they told me that "it doesn't always work...".

Is there a reliable way to "release" an old unused ASM disk "on-the-fly"?

    Stuart