Assuming you have done the previous step of reorganizing your code, now can get ready for the migration to actual micro-services. Your monolithic architecture should be looking more or less as follow:
The term Brownfield (used in IT) means that we are going to do development and deployment of new software systems while taking into account previous existing legacy software systems. The term Brownfield originates from the contemporary civil engineering where in some cases required that new buildings were designed and erected while having in consideration other structures and services already in place. In our case, transforming a monolithic system into a micro-service system can be considered Brownfield.