Another blogpost about KMS again. Before this 3 other blogposts where available, just have a look at that one also:
Key Management Services (KMS) explained
Using KMS Client Setup Keys during deployment
Usage of Microsoft Office 2010 KMS Host License Pack
The Microsoft Office 2013 KMS Host License Pack must be installed before importing the KMS key. It can be downloaded at this location: Download Center. During installation the Office 2013 KMS key can be imported successfully.
Volume license editions of Office 2013 client products require activation. This download enables IT administrators to set up a Key Management Service (KMS) or configure a domain for Active Directory-Based activation. Either of these volume activation methods can locally activate all Office 2013 clients connected to an organization’s network.
Just make sure your KMS host is running on Windows 7, Windows 8, Windows Server 2008 R2 or Windows Server 2012.