SQL Server 2014 Core Licensing in VM Environment

Over the next several months we will be deploying a new virtual PROD/DRS/Test system for one of our customers. Each DB Server has 6 cores. Our procurement department purchased EMBD SQL SVR ENT 2014 EMB ESD OEI 4 CORE ENT for each DB Server. They also purchased EMBD SQL SVR ENT 2014 EMB ESD OEI 2 CORE ADDTNL LIC ENT to cover the 6 cores for each server.

We activated the 4 core, but we are not sure how the 2 core additional works. Does the 2 core have to be activated on the servers as well and if so how do you activate the 2 core as it is just a set of numbers.

Thank You,

Margaret