...
If uploads are not allowed from the web (changable via a runtime property), you can drop the omod into the ~/.OpenMRS/modules folder. (Where ~/.OpenMRS is assumed to be the Application Data Directory that the running openmrs is currently using.) After putting the file in there simply restart OpenMRS/tomcat and the module will be loaded and started.
Tips While Developing Your Module
It is a tedious task to build and install the module each time you change something and you want to test it. In order to make the process slightly more efficient you can add the following snippet to your omod/pom.xml:
...