To be able overwrite default JAX-RS provider(s) developer need:
Deploy own RESTful service(s) by using subclass of javax.ws.rs.core.Application (hereinafter Application).
Service(s) NOT NEED to implement marker interface ResourceContainer and MUST NOT be configured as component(s) of eXo Container. Instead of it Application must be configured as component of eXo Container.
If RESTful services or providers require some dependencies from eXo Container then Application should inject it by own constructor and then delegate to services or providers. As alternative method getClasses() may be used for deliver services/providers classes instead of instances. In this case services/providers will work in per-request mode and RESTful framework will take care about resolving dependencies.