The Civil Filing Main Line phone number is (210) 335-2621. All Texas residents can apply for a name change under Texas Family Code Chapter 45.In general, Texas has very few official legal forms. Civil Filing accepts all new suits and subsequent filings for civil and some family related matters filed in the Bexar County District Courts. We do how ever want to have the same last name. How do We go about changing her last name to mine? To ask a court for your name change, you send in a petition that includes basic identifying information and a fingerprint card. Legal Name Change Attorney in Bexar County. Fast, professional, and thorough. Legal Name Change Attorney in Bexar County.