on the first step "1st, Download and run Get Ready For IPS 4.0 1.0.3 to test your current install to see if it is in fact ready. you can get your copy here." do i need to upload it to my website back end? 

Yes. You can place the php-file in the same root folder as your forum installation, where the files conf_global.php and initdata.php also lies.

Then you just visit the file on the same url as your community in your browser. Ex: yourcommunity.com/installCheck.php

I'm not sure I remember the exact name of the file, as I'm not on my PC right now, but just use the name for the file basically