Go to the S3 console: https://console.aws.amazon.com/s3
awsworkshop-concurrencysample-us-west-2 in the search bar of Buckets. Then select the radio button to the right of the retrieved bucket. Then press the Empty button at the top.
To activate the Empty button of the empty bucket, enter the bucket name and press the Empty button to delete all bucket.
When the message that the deletion is complete appears, click Exit on the upper right to complete.