How to migrate image datastore


We have 2 datastores for images, but now we’d like to use only the second one. So we clone all the images from old datastore to the new one. But we have problems with images marked as USED. It’s seems that running VM with their DISK SOURCE pointing to the old image are preventing us to delete the image from the old datastore, even if they exist in the new one. How to deal with that ?
I try to update vm configuration, changing disk source

SOURCE = “/var/lib/one//datastores/1/e26f81bd52650965ca511a31aa4a2249”,

To the new location/hash. No success.