Welcome to the Amplitude error detection beta. To delete event types, first go to the advanced tab - you can get there by clicking the link in the email we sent, or by going to "manage data," selecting the project you want to delete events from, and then clicking "advanced."
From the "advanced" section, select the events you want to delete, and click "delete."
A dialog will show up with a confirmation process. Upon completion of this process, the events will be deleted. Note that the deletion of event types is permanent and irreversible.