Which section of the TOGAF document describes the processes, skills and roles to establish and operate an architecture function within an enterprise?

Part II: Architecture Development Method (ADM) describes the iterative method for developing an enterprise architecture, focusing on the steps, not the capability itself.

Part III: ADM Guidelines and Techniques provides supporting guidance for adapting and using the ADM, not the framework for establishing an architecture function.

Part IV: Architecture Content Framework describes the content meta-model and artifacts that are created during the ADM, not the operational aspects of the architecture function.

Part VI: TOGAF Reference Models provides a set of architectural models for common architectural styles, not the management of the architecture capability.

Part VII: Architecture Capability Framework of TOGAF provides a structured approach for establishing an architecture capability within an organization. This part details the processes, organizational structures, roles, responsibilities, and skills required to successfully operate and manage an enterprise architecture function.