You sign and date the Form 1040-X on page 2.
You do not include the Form 1040 nor any informational forms with the amended return.
You would only include with the Form 1040-X other forms that were changed due to amending your original tax return. If any other Forms or Schedules were included with your print out they will have an Attachment Sequence Number located in the upper right corner of the Form or Schedule.
If no no other Forms or Schedules were printed, then you only file the Form 1040-X.
