How can I replace a target celerra with a VNX without re-replicating.

I have an NS960 at production replicating to and NSG conneted to a CX480 at the DR site.I am replacing the NSG and CX480 with a new file/block VNX7500. Is there a way to replcace the NSG/CX480 with the VNX without re-replicating. I want to avoid having to move the NSG/CX480 to production as per the silvering method. I also want to avoid tape. I have heard that this can be done by using the already synced copy on the NSG to populate the VNX but I can't find a procedure.