Activating additional Cisco MDS 9124e modules and extending fabric

[Cookiejc10]

Hi, We have a c7000 system with two 9124e modules operating two separate fabrics. There are an additional 2 modules in the system which are currently unused / unlicensed. Can anyone offer any advice on bringing the additional modules online? I understand we will need the licenses but  I am unsure as to how these additional modules will connect to the existing two fabrics which have the connections to the SANs.

The main requirement for enabling these switches is that we need more external ports. The blades within the chassis have all the connectivity they need.

Any advice would be greatly appreciated