Copy all files except this readme and the Optional folder to your
SRIV installation folder (C:\Program Files (x86)\Steam\SteamApps\Common\Saints Row IV).

If you want White House Outfits for Spaceship Homies:

After following the instructions above, copy the character.xtbl from the optional folder
(in the White House Outfits for Spaceship Homies subfolder) to you SRIV directory and overwrite.

Enjoy your stylish homies!