Indian Passport - Last Name Change from Maiden to Married

[PSB]

I & my wife have come here on L1 & L2 visas respectively. My wife had her maiden name on passport and visa when we got here. We are thinking of changing her last name on passport to after marriage last name which is my last name. I looked at the online for applying for name change but got stuck with couple of questions. If anybody can help answer below questions -

1) Where should we enter the new and the old last name on the online application form? i.e. What are the field names for these.

2) Which address do we need to provide? Indian or US? We are going to be here for another 7-8 months. Considering that what address should I provide?

[PSB]

Can anyone help answering these questions urgently?