Convert rails + angular + devise app to rails + angular + devise token auth app

I currently have a rails app, served completely from the asset pipeline, which uses regular devise with sessions etc to do authentication and all that. I need it converted to angular outside the asset pipeline, using ng_token_auth on the frontend, devise_token_auth on the back, and the login screen to be angular-ified. I want all existing users to be unaffected. All the javascript libraries should still work, and I should be able to deploy the whole lot to heroku and it work. This is a simple translation from one system to another. I just don't have time to implement it at the moment.