Fire TV Gamer Version Install

I have installed Kodi before on different devices. My Brother got a Fire TV Box that I am trying to install Kodi on from http://kodi.tv/download or whatever your link is. I use ES Exp. Like I normally would and when I click download and then when I try to insall a window pops up asking how I would like to open this file with options such as text, photo Other etc…

Can someone assist me? Everyone eeps saying the install is same as fire stick. I have never run into this.

Thanks