How do I safely delete an already created "User"?

Twitter login is being implemented on Rubu on rails.
For that reason, I would like to create a user model for login.

I typed the following command to the terminal to create a user model.

./bin/railsg model user provider:string uid:string nickname:string image_url:string

The following error message was displayed:

Running via Spring preloader in process 66801
      invoke active_record
The name 'User' is either already used in your application or reserved by
Ruby on Rails. Please choose an alternative and run this generator again.

As far as the error message goes, "User" has already been used, but since I want to create a new model, how can I delete the existing "User" and create a new user model?

That's it