sudo apt install gnome-tweaks
sudo pacman -S gnome-tweaks
Start by creating the directories where the icon themes will be stored.
cd ~/
mkdir .icons && cd .icons
Proceed to clone the github repo to the current directory.
git clone https://github.com/rohansharma-developer/GTK_icons.git
Copy all the contents of the folder to .themes
cp -r ./GTK_icons/* ./
Open gnome-tweaks
from your app menu. Choose any theme of your choice. Enjoy!