Well, I keep referring to my "own":https://www.tongfamily.com/gadgets/blackberry/chinese_blackberry_and_cingular_blackberry.php page that explains how to install Chinese input on the Blackberry.
The two main steps that work for Blackberry 8700 and 8300 Curves is:
* "Hong Kong CSL":https://www.blackberry.com/Downloads/entry.do?code=EEFC9E10EBDC4A2333B42B2DBB8F27B6 is still after two years the easiest way to get the Chinese versions. These are not multilingual. Chinese is handled as its own build.
* Delete c:\program files\common files\research in motion\apploader\vendor.xml so it forgets to match your phone with the firmware version
* Run the Desktop Manager and do the application installatoin.