This will be the easy part of interacting with StructureMap. During application execution, you will need to resolve the services you previously registered in the container. When you ask StructureMap to resolve a service, StructureMap either creates a new object instance or finds the previously built object for the correct Object Lifecycles.
While in many systems you will probably only resolve the default service of a type or a named instance of a service, there are far more ways to resolve services exposed by StructureMap. The IContainer interface acts as a Service Locator to build and resolve configured services on demand.