Go to your crate's settings page on crates.io. Press the "Delete this crate" button to delete the crate. Currently, the requirements to be able to delete a crate are:

A crate can only be deleted if it is not depended upon by any other crate on crates.io. Additionally, a crate can only be deleted if either:

• the crate has been published for less than 72 hours

or

• the crate only has a single owner, and

• the crate has been downloaded less than 1000 times for each month it has been published.