Так вроде прям на главной описано
https://github.com/thoughtbot/clearance#views
To override a view, create your own copy of it:
app/views/clearance_mailer/change_password.html.erb
app/views/passwords/create.html.erb
app/views/passwords/edit.html.erb
app/views/passwords/new.html.erb
app/views/sessions/_form.html.erb
app/views/sessions/new.html.erb
app/views/users/_form.html.erb
app/views/users/new.html.erb
You can use the Clearance views generator to copy the default views to your application for modification.
rails generate clearance:views
