The Office 365 Team released an update which now makes "Switching between Office 365 Plans" possible. There was a very strong Ask from the community which the Product Team heard and incorporated.  The article on the Office 365 team blog : Office 365 customers can more easily switch plans talks about how you can use the "Switch" feature from the Office 365 Admin Center. This used to be road blocker for deployments and to achieve some of the "Switching scenarios" there was no option but to go for third party migration tools.