Yes, you can revise your preprint at any time by going to "My Submissions" and from there select the preprint you'd like to edit. It will pop open the submission page and from there you can edit your information or upload new files. Note that your paper may need to go through another moderation check after revision. If the revision passes moderation, it will appear as a new version of the preprint on the same Advance page - the initial version will still be accessible. If you need additional help, check out the How To Guides.