You already have seen how you can create axis2 web service with axis2m on getting started guide; if you have not gone through the getting started tutorial please go through it first. If you want to add more services or change a service, there is no special procedure, as usual create all of your java classes in src/main/java/src floder then modify the service.xml file according to them, you can find service.xml file in the following location.
src/main/web-app/WEB-INF/services/{ServiceName}/services.xml