Step 1 - Install this lite version of Windows Phone 8 SDK and it's prerequisites from here (works on Windows 7, includes Developer Unlock and stock WP8 SDK XAP deployment)
Step 2 - Install Visual Studio Express 2010 (yes 2010) from visualstudio.com
Step 3 - Download Windows Phone Power Tools from http://wptools.codeplex.com/
Step 4 - Now Power Tools should install, since it has the required resources, albeit older ones, to install.
Step 5 - Uninstall Visual Studio 2010 if desired (you can by opening it's install thing again). Not necesarry I don't believe.
Step 6 - Enjoy WPPT on Windows 7 =D
Sorry if something like this was posted already.