You may edit a preprint at any time. To do so, log in to your account, click My Submissions, and click the row containing the submission you want to edit. You may edit your metadata and upload new files; to reorder or delete old files, click the Manage link. Once everything is ready, check Publish Changes at the bottom of the window and then click Save Changes to send the revision to TechRxiv. Your original posted preprint will remain online while a TechRxiv moderator screens your revision. Once the revision is approved, the posted preprint will be updated with the new material. Your original version will remain publicly accessible with a date and time stamp. Revisions will have the same DOI as the original preprint plus a version indicator.