How to remove the AWS Backups
Coincidentally I had to do something very similar yesterday. This is the script I used:
#!/bin/bash -e

VAULT_NAME=...   # put your Backup Vault name here

for ARN in $(aws backup list-recovery-points-by-backup-vault --backup-vault-name &quot;${​​​​​​​VAULT_NAME}​​​​​​​&quot; --query 'RecoveryPoints[].RecoveryPointArn' --output text); do
  echo &quot;deleting ${​​​​​​​ARN}​​​​​​​ ...&quot;
  aws backup delete-recovery-point --backup-vault-name &quot;${​​​​​​​VAULT_NAME}​​​​​​​&quot; --recovery-point-arn &quot;${​​​​​​​ARN}​​​​​​​&quot;
done

You can also add --by-created-before to delete the old backups only.
Hope that helps :)