Tang's Alterations 8669 Sudley Rd, Manassas, VA20110 Tang's Alterations offers a complete line of alteration services, from simple hems to intricate bridal gown…More modification. It specializes in formal attire. Even the most complex jobs come with a customer satisfaction guarantee. The staff provides individual consultations and can advise customers about the best approach to each unique project. Average turnaround time for most jobs is one week.