Help cant make it to svheduled bio appt

Hey guys need help i expire March 20th 2015 , I mailed my renewal on the late side it was received dec 11th just got my bio appt letter for jan 15 I work that day and can't take off . I'm Schedule to go to the uscis in philly I' want to attempt to do a walk in prior to my scheduled date , has any one ever walked in at this location if so did they let you. I was going to drive super early be the first one there n see if they let me

Try to walk in. Worst case scenario they'll turn you around and that'd be that.

Other than that you have a check box asking for a reschedule on the letter. You mark it, and send the form to the provided address.