If the current switch is not reacheable through netsight, stored backup configurations can be retrieved by using the Inventory Manager > Archive Mgmt Tab > Select the configuration you want to restore from the tree Archives to the left (open the subtrees until you select the configuration and not the folder) > right click on the file > copy file to client > save as a zip file. Inside you will find both a .cfg and .xsf of the backup config. Then upload the final manually.
If the switch is in sync with netsight you can restore the configuration through One view > Right click on the device > Configuration > Restore configuration. The same is valid by accesing the inventory manager.