CREDITS:
Original portraits created by ConcernedApe (http://twitter.com/concernedape)
Modded portraits created by Kamirose (http://twitter.com/kamirose)

RECOMMENDED:
First, back up your Stardew Valley\Content\Portraits\ folder!
You can do this by simply copying it to a different folder.

INSTALLATION:
Extract files into your main Stardew Valley directory. For steam installs, this is by default:
C:\Program Files\Steam\steamapps\common\Stardew Valley\

If you install to the correct directory, the files will be merged into the correct folder.
Select 'yes' for any file overwrite prompts.

UNINSTALLATION:
Delete your Stardew Valley\Content\Portraits folder.
Restore your backup!
If you did not make a backup, you can have steam "Verify the integrity of your game cache," but this may
remove other mods as well.