If you just want it to be smaller, maybe you can modify scaling in characterinfo.txt.
Not sure what client you are using, so it might not work.
In top-recode, the client source had it disabled, but easy to enable.
In characterinfo.txt last 3 floats, eg, 1.0,1.0,1.0 for Long Haired Guy (ID 1) .
In SceneCreateNode.cpp, function CCharacter* CGameScene::AddCharacter(int nScriptID)
// added by clp 设置缩放
// Comment this out
//scale.x = 1.0f;
//scale.y = 1.0f;
//scale.z = 1.0f;