Yeah you need to download the SDK for that. Try using an app like root explorer or android mate (a file manager that does root/read write access to /system partition) and delete HTC_IME.apk (from /system/app, /data/app, /data/app-private/ etc, wherever it is) then try again.
AFAIK, the only file this version of the keyboard unpacks on install is that libt9.so file, so if that's not there, only other thing I could think of would be that a different version of HTC_IME.apk is somewhere on your phone already. Perhaps try seeing if there is a touch input listed as an application you can remove in settings/applications/manage applications as well.
Other then that, I think use of adb is the only way we can really solve this.
Awesome tip! Thanks! I found an empty folder for the HtC keyboard in my /data/data folder. Using Android Mate I found it and blew it away...
Installed the new .apk file...