The guide outlines the necessary changes developers must make to update their Kibana plugins for compatibility with version 6.4, emphasizing improved ease of plugin development. Key updates include replacing the "uses" array with explicit imports, modifying the visualization loader to directly accept filters and queries, and introducing the Inspector to replace spy panels. Developers working with editor states are advised to adjust their code depending on whether they're using Angular or React, with specific instructions for managing editor parameters. Angular dependencies are being reduced, with services like RegistryFieldFormatsProvider and the Timefilter Angular service undergoing significant changes, including the transition to singletons and the introduction of new event handlers. These updates aim to streamline the plugin development process and enhance compatibility with newer Kibana versions.