The easiest way to try out an OpenMRS 2.x release is by downloading an OpenMRS 2.x standalone.
If you want to install for production use, you will need to install the WAR plus modules.
An OpenMRS 2.x release consists of:
At http://openmrs.org/download/, for a specific release of OpenMRS, you can find one link to the WAR file, and second link to Modules & Data.
The first step is to ensure that all prerequisites (e.g. Java, MySQL, Tomcat) are installed. (To Do: link to documentation of prerequisites.)
Next, you deploy the OpenMRS Platform WAR in Tomcat (or another servlet container). Next, visit the deployed URL (e.g. http://localhost:8080/openmrs) and you should see a first-time setup wizard. (To Do: screenshots).
Go through the first-time setup, making sure you do not install demo data.
Once the wizard has configured the database, you should see a login screen. You don't need to log in – at this point you have installed the OpenMRS platform, and you want to install all the modules, which you will do from outside of OpenMRS.
Next, you need to find your OpenMRS modules folder is. Typically this will be the "modules" folder next to the "openmrs-runtime.properties" file that was created by the first-time setup wizard.
Once you have found this folder, you want to copy all of the OMOD files from the "OpenMRS 2.x Modules and Data" zip (downloaded from http://openmrs.org/download/) into your modules folder.
Next, restart Tomcat.
This time, the OpenMRS application will take an unusually long time to, since a lot of reference data is being created for the first time. You can watch progress in tomcat's logs. Finally, when you visit the deployed URL you should see a login screen that looks different from what you saw after installing only the Platform. (It should look like the one on http://demo.openmrs.org/.)