Delete all firebase functions

Sign in to your Google Cloud Console at https://console.cloud.google.com, select your project, then from the list on the left pick Cloud Functions. When you get the list of functions, click the check box on the header line to select all, then the Delete button in the tool bar.

Update for comment:

I don't know what the product strategy for Firebase Console is with regard to Cloud Functions. My guess is that it is intended to provide a simplified, more convenient interface for managing Firebase related cloud functions. The Google Cloud Console provides a richer set of capabilities for managing functions and viewing logs. You could submit a feature request to Firebase to get those capabilities added to the Firebase console. Some details on the Firebase/Google Cloud relationship are provided at these links:

https://stackoverflow.com/a/42859932/4815718

https://cloud.google.com/functions/docs/concepts/functions-and-firebase

Just comment (or delete) all the functions in your index.js file and redeploy it through the CLI.