Inclusion of surname on passport

hi,,

I have a Indian passport with my First Name and Surname written together(By Mistake) and, my Surname space is empty. My passport is 8 yers old. I would like to put my Surname on my passport.

My question is what is the procedurte and will i get a new passsport?? or old passport with the edited details.

Actually I would like to keep the old passport as it has different Visa stamps..

I would really apperoicate any help and suggestion .

Thanks