Read these link for how to request expedited processing for biometrics appointment:
http://www.familytousa.com/family-to-usa/2012/1/14/requesting-expedited-biometrics-appointment-for-re-entry-per.html
https://www.uscis.gov/archive/archive-news/uscis-biometric-changes-re-entry-permits-and-refugee-travel-documents