Well, you copied them, so why would you expect it to change???
You need to edit them yourself, then put those edited models on the right path using the method I stated above
For example, let's say the Footman models path is Units\Human\Footman\Footman.mdx
then you see an awesome model in hive and want to replace all Footman with that model:
You create the Units Folder
Then create the Human folder
Then create the Footman folder
Put the downloaded model inside the Footman folder
rename it to Footman.mdx