you can connect the boot disk directly to you desktop and then copy the license file.  then you can svc_reinit to reinitialize the system to factory default.   
Hi all, I have just received a Unity 300 and I have some questions about it.  I found we can restore to default the system switching controllers to service mode but I supose that procedure wipe out the license, isn't it? As we are not the original customer I don't know if I can access to download license file. Is any way to obtain the license from system before restore it to defaults? Thanks in advance,
UNITY 300 restore to defaults