I just called the USCIS hotline 1-8003755283 to change my address and it is weird that the customer rep told me they cannot do it by taking the call and all I need to do is to change the address online.
However, based on the info I found on their website http://www.uscis.gov/files/article/G3_English.pdf , I need to do both and I do have an option to change the address by dialing the 800 number.
Has anyone have the same experience?
Thanks.