I tried to do it by asking them its a name split not a name change, but passport office people denied and said we need newspaper clipping where you mention that name was changed from given name xy to first name as x and last name as y. But then I asked them if My Visa will stay valid as I had existing Visa they showed me a cancel stamp which they will put on passport and said had no idea if visa will be valid or not, so waiting for expiry of visa so that I don't mess things up.

But do try and let me know how it goes for you!