changing surname after getting VISA stamped

Dear All,.

My surname is blank, and full name is entered into my given name column in my passport. Now I want to put my fathers name in surname column. But, the main thing is, my H3 petition is already approved with present passport with surname as my full name and first name as FNU and I have my interview at US embassy in 5 days.So, I was wondering if I could change my surname after getting VISA.Someone please help in this regard. If it is possible, what is procedure? do they make any observation in the present passport or issue a new passport ? If they issue a new passport, what about the old one with VISA stamping? I learnt from few of my friends that having surname is very imp in US, so am desparate to fix this issue. Very soon I will be moving to US. Please help in letting me know the possible options before me…

Awating…