First you'll have to configure your computer with the right domain name suffix:
http://kb.mit.edu.ezproxyberklee.flo.org/confluence/x/JgNt
After that, you'll have to put your computer on MIT'S network by using the VPN client:
http://ist.mit.edu.ezproxyberklee.flo.org/cisco-anyconnect/all
After you have applied the correct domain name suffix, restarted your computer and launched the VPN, Office should activate automatically the first (or second) time you launch it.
...