Here's the response from ATF when asking about change of address for FFL 03:
Thank you for contacting the ATF’s Federal Firearms Licensing Center (FFLC) with your e-mail inquiry.
You will need to submit ATF Form 5300.38, Application for an Amended Federal Firearms License. You may download the form at:
http://www.atf.gov/forms/download/atf-f-5300-38.pdf .
As a collector you must complete all items on the form except items 4,14,15,16, and 17. All references to "business" should be considered "collecting activity." Mail the form along with the original license to:
Federal Firearms Licensing Center
244 Needy Road
Martinsburg, WV 25405