Change of surname after marriage

Hi,
I am in UK as dependant (spouse) of settled person and have been granted the initial 2 year visa.I have been using my maiden name which was in my passport till now for all my visa applications.I want to change my surname to my married name now-

-Can I get my surname changed in my passport(Indian) only and change it on visa the next time I apply for visa extension(after 2 years) or do I have to get it changed on the visa now itself and transfer my new visa on the new passport?

-will my marriage certificate be acceptable as evidence (they granted dependant visa on the same certificate) or do I have to get deed poll?

Would really appreciate any help as I have been unable to find anything useful on the UKBA website.

Thanks