If you've accidentally started an Alternate Submission and you don't want to submit it, you do not need to delete it! Any submissions that you have not submitted and finalized will not be received by the Project Owner (or purchaser).
If you've already finalized your submission but would like to withdraw it, you can do so by viewing your Completed Submissions against the Opportunity and clicking View Receipt:
You can then un-submit by clicking on the link, bringing your submission back to Work-in-Progress status so that it will not be received by the Project Owner.
If you have any questions, please contact Support@GoBonfire.com.