Before latest steps updating version
Use this scenario when one or more small hotfixes are required in order to address a specific issue, but business factors such as time or cost limitations prohibit a complete application update.This process is required before you can use scenario 3.If your environment is already live in production, the source database is a copy of the production database.Otherwise, the source database is your most current database.After you've completed the code migration, continue to scenario 3.These steps apply to customers who are live on an earlier release and want to do a full upgrade to the most recent platform and application releases.It helps the developer verify that the data upgrade can be completed successfully by using the specific set of customizations in this environment.To make a copy of your production database, follow the steps in Copy a Microsoft Dynamics 365 for Finance and Operations database from Azure SQL Database to a SQL Server environment.
It describes the overall process and the supported scenarios, but doesn't provide detailed instructions for every step of the process.
All features in the current update of the application are available individually on Microsoft Dynamics Lifecycle Services (LCS).
For more information about how to download hotfixes from LCS, see Download hotfixes from Lifecycle Services.
The steps might also apply to customers who have already deployed and configured a production environment, even if they haven't yet gone live.
If you aren't upgrading your application but just want to upgrade your platform, use scenario 4 instead.
Search for before latest steps updating version:
Before you upgrade, you must have have a plan to refactor your customizations into extensions.