A method for replacing an existing generator frame that supports a generator of a wind turbine includes removing the generator from atop the existing generator frame. The method also includes dismounting a control cabinet of the wind turbine from the existing generator frame. More specifically, the control cabinet is electrically connected to one or more wind turbine components via a plurality of cables. The method further includes relocating and securing the control cabinet to an uptower location within a nacelle of the wind turbine with the plurality of cables remaining electrically connected. As such, the method includes removing the existing generator frame from within the nacelle. Moreover, the method includes installing a new generator frame in place of the removed existing generator frame. Thus, the method also includes remounting the control cabinet to the new generator frame.