Reviewers cannot modify an attachment directly. Instead, a reviewer must call or email one of the eGC1 Owners (e.g. PI or Contacts) to request a change.
A reviewer can also click the Return button on the Approval Graph page to remove the eGC1 from the routing process and return it to the Preparer for updating. This is only recommended, however, if the item that needs modification will impact all reviewers, as it delays the routing process.