I'm not sure I understand the question. The disk enclosures behind your DS4500 would stay there. You would provision LUNs from the DS4500 and present them to the V3160. The V3160 could not use the IBM disk enclosures. It can only use NetApp disk shelves or LUNs provisioned by a supported 3rd party storage array.
You can read the Installation Guide for IBM Storage for directions on how to implement your V3160, or you can contact your NetApp account team for assistance.
http://now.netapp.com/NOW/knowledge/docs/ontap/rel734/#V-Series Specific Documentation
If I've misunderstood your problem, please do clarify.