How to swap licenses
To swap a license (for example from Office 365 Business Essentials to Business Premium) you will first have to order the new license you want. For a full detailed instruction for this, see the following document: How to order Microsoft Cloud Services
When you have ordered the new license, upgrade the number of seats for this license to the desired amount. For a full detailed instruction for this, see the following document: How to upgrade/downgrade number of licenses
The next step is to assign the new licenses to your users. For a full detailed instruction for this, see the following document: How to assign and release licenses from users
When the licenses have been assigned to the users, release the old license from the user.
For a full detailed instruction for this, see the following document (Step 8): How to assign and release licenses from usersWhen the old licenses have been released from the users and you don't need the license anymore, you can cancel the subscription. For a full detailed instruction for this, see the following document: How to cancel a Subscription
It is important to first assign the new license and then to release the old license from the user. If you deviate from this order, the user will experience license issues.