How to change Office 2013 keys

For 32 bit Windows:

cscript "C:\Program Files\Microsoft Office\Office15\OSPP.VBS" /inpkey:yourkeygoeshere 

For 64 bit Windows (assuming you are using 32 bit Office):

cscript "C:\Program Files (x86)\Microsoft Office\Office15\OSPP.VBS" /inpkey:yourkeygoeshere