1)Run 7TSP GUI.

2)If you encounter an error message stating, "Sorry, 7tsp only works with Windows Se7en!" then proceed with the steps below, otherwise move on to step number 3.
This is only applicable to WIndows 10 builds.
  Right click on 7TSP GUI & slect properties.
  Under the Compatibility tab check the 'Run this program in compatibility mode for:' box
  From the dropdown menu select Windows 7 & click Apply.

3)Click on Add A Custom Pack & select your desired 7TSP compatible pack. For any Windows 10 builds, you must make sure the icon pack you are attempting to install 
is compatible & compiled specifically for that build.

4)Click on Start Patching & by default settings 7TSP will create a restore point & install the contents of the pack.

5)Once installation is done, reboot.