Replacing a RP CX4 CRR target with a new VNX

Hello, everyone.  I have a RP/SE environment currently doing CRR from a VNX to a CX4 across a WAN link.  The CX4 is being replaced with a VNX.  The current GEN4 RPA's at the target site need to be integrated with the new VNX, and then the CG's need to be reconfigured so that the target copy of the protected volumes land on the VNX. 

I have found the repository migration document.  That doesn't help me put together a strategy for migrating the target copy from the CX to the new VNX.  I really don't want to have to do a full reseed over the WAN link.  Is there a supported method for doing this?