Identify logical components.
Flatten and refactor components.
Identify component dependencies.
Identify component groups.
Create an API for remote user interface.
Migrate component groups to macroservices (move component groups to separate projects and make separate deployments).
Migrate macroservices to microservices.
Repeat steps 6-7 until complete.
https://www.atlassian.com/microservices/microservices-architecture/building-microservices