word segment module in spamassassin

Hi!
I’m researching about spamassassin on centos 6. I want to improve spamassassin to prevent SPAM email that written in Vietnamese language, and i will use Bayes filter to caculate probability for tokens. I have a question:

I want to replace word segment module in spamassassin by Vietnamese word segment module , but i don’t know how to replace?

Thanks!