Part 1 discusses the key architectural differences to be aware of between Google Apps and Office 365, when performing migrations. You will get detailed information about how to prepare for your migration. You will also see a demonstration of the most common migration strategy: Pre-Stage Migration.
Part 2 demonstrates a more complex strategy that can be followed for very large migration projects. Be sure to also watch Part 1 when you are performing large migrations; it includes key planning and preparatory information for your project.