Abstract: A method for converting a turbine casing of a turbine having an axial flange relative to a rotational axis of a rotor of the turbine, and having a radial hot gas inlet relative to the rotational axis includes the steps of: axially separating the turbine casing into two axial sections so as to form a separation zone, wherein the first axial section has the flange and the second axial section has the hot gas inlet; rotating the two axial sections relative to each other around the rotational axis so as to transfer each of the two axial sections from an original old relative position into a new relative position; and connecting the two axial sections to each other in the new relative position along the separation zone.