Wipe all stored prometheus metrics?
Solution 1:
Prometheus stores its TSDB in /var/lib/prometheus in most default packages.
It will initialize it on startup if it doesn't exist so simply clearing its content is enough.
If you've played around with remote_write however, you'll need to clear the long-term storage solution which will vary depending on which storage solution it is.
If you want to reset its configuration, delete /etc/prometheus and reinstall the package.