I'm in charge of a website developped with symfony. This website is in prod.
I would like to know how to reinstall the front-end console, because im completely blinded in my task.
I suspect you're talking about the "Web Debug Toolbar":
You can control the visibility of the Web Debug Toolbar in the settings.yml. Set the web_debug parameter to true for the environment you're using. After clearing the cache with symfony cc the toolbar should be visible.
But be warned: enabling the toolbar, will make this visible to all visitors! You probably don't want this!
So depending on your problem I'd first go for enabling logging in production, and analyze the logfiles. If that doesn't solve your issue, copy the frontend_dev.php file to your production server, update it's IP to match your own, and set the environment to test. Next, set the web_debug property in test to true. Clear the cache, and navigate to this scriptfile. This way you can test, while normal users can't access the debug bar.