`overwrite=True` explicitly:  
```python
>>> from huggingface_hub import metadata_update
>>> metadata_update("username/my-cool-model", {"pipeline_tag": "text-generation"}, overwrite=True)
```  
It often happen that you want to suggest some changes to a repository
on which you don't have write permission. You can do that by creating a PR on that repo which will allow the owners to
review and merge your suggestions.  
```python
>>> from huggingface_hub import metadata_update