RRO tool for off-line use
Using the tool on your local computer: unzip RRO_tool.zip, this will result in a directory called RRO_tool. Navigate to that directory, locate the file index.html, and open this file (preferably in a modern browser such as Firefox or Chrome).
Installing the tool on a company web-server: unzip RRO_tool.zip, this will result in a directory called RRO_tool. Copy that directory to a company webserver (or ask the server administrator to do this for you). There is no further configuration required, the tool should be functional from the location where it has been copied.