How to delete logs on Google App Engine?

I misconfigured a deployment to GAE (the 'Flexible' varient), and let it run for a couple of weeks. I had NOT made a route for _ah/health and it got pinged every four seconds by the GAE infra - causing exceptions to hit the logs courtesy of the web framework. Logs filled to 35GB which is where they sit today, after I made a route for the underdocumented healthcheck route. I can't find anything in the UI to allow me to delete those logs. https://console.cloud.google.com/logs/ is the main place for viewing logs, but there's no clue within as to how to delete them.