After installing, launch ImageJ and under the Plugins menu, select the Open MIMS Image. This will open the plugin. Files can then be opened either using File>Open MIMS Image or by dragging and dropping a file over the graphical interface.
If you are having issues opening images try opening the sample data file. If you are unable to open the sample than the problem most likely resides in the installation process. Make sure to overwrite/delete all previous versions of any .jar files that may exist in your 'plugins' directory. If you are able to open sample data but not your own images, please contact us with any error report that may have been generated at the following email address: