Explanation
You can upgrade (or downgrade) EPLDs using CLI commands on the Nexus 7000 Series device. Follow these guidelines when you upgrade or downgrade EPLDs:
*You can execute an upgrade from the active supervisor module only. All the modules, including the active supervisor module, can be updated individually.
*You can individually update each module whether it is online or offline as follows:

-If you upgrade EPLD images on an online module, only the EPLD images with version numbers that differ from the new EPLD images are upgraded.

-If you upgrade EPLD images on an offline module, all of the EPLD images are upgraded.

*On a system that has two supervisor modules, upgrade the EPLDs for the standby supervisor and then switch the active supervisor to standby mode to upgrade its EPLDs. On a system that has only one supervisor module, you can upgrade the active supervisor, but this will disrupt its operations during the upgrade.

*If you interrupt an upgrade, you must upgrade the module that is being upgraded again.

*The upgrade process disrupts traffic on the targeted module.

*Do not insert or remove any modules while an EPLD upgrade is in progress.

Reference: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/4_0/epld/release/notes/epld_rn.html