How to Change the Language?

[yangdh]

I installed the latest yellowdog packages successfully in my dual-G5 2G 
Hz, and ran well.  I would like to change the interface from English to 
Chinese but I don't know how to do it. There is nothing in System 
Settings->Language window and no means to add one.  I added 
kde-i18n-Chinese package, no avail.
I tried to find in yellowdoglinux support website, nothing relevant 
found.
Could some inform me how to change the language?

thanks in advance.

dehua