HowTo import Cyrus Mail-Dir into Thunderbird, without Cyrus?

[Alexandros Gougousoudis]

Hi,

one friend got a copy of his maildirectory in Cyrus from the admins of 
his university when he left. They told him, he can import it into 
Thunderbird and use the old mails. How can this be done? Is there a 
converter?

We're using also Cyrus, all emails are single files in 
/var/spool/cyrus/mail/user, I don't know any way how to use these files 
with a mailreader without the serversoftware.  Any hint is welcome

TIA
 Alex