Double-click on the downloaded Exe file. A windows like this might open, because I haven't bought an expensive certificate to sign the file:
Nevertheless, you can install the program by clicking on the highlighted text link on the lower left, labelled with "More information" or something alike.
Prerequisites
IrTool uses the .NET Framework version 4.5 and some Visual C++ Runtime Libraries. They will be installed if they are not already on the system.
Note
Newer versions can be installed on top of existing versions without deinstallation.
After the installation, there are some sample files in the folder "Documents\IrTool Samples"
you can use tro try the software out, even when you didn't register your camera yet.