How to use iwep pro

I've already read how to use it here, but honestly, I can't get it to work. I have the dictionaries installed, but when I open it, it tells me I have to install them, even though they're already installed. I also saw that it says I need to know how to install .deb files, but I didn't understand how to do that either, no matter how hard I tried. I hope you can help me. Thanks.