To install OMORE, just go the OMORE Web site and follow the link in the download section (omore-1.0.xpi). Firefox automatically shows a installation dialog where you are asked if you want to install the OMORE. A restart of the Firefox Web browser is needed to complete the installation process of OMORE.
It may be that OMORE does not work properly with the installed Java environment of the system.
Open your control preferences and select the Java Control Panel. In the Advanced tab you'll see an option that controls the behavior of Java in Web browsers. Just deactivate the option next-generation Java Plug-in. After the restart of your Web browser OMORE will work properly.