Task is very simple:
Open terminal and type in commands:
wget -c https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
This will download the latest Google Chrome deb file which You will install it using this command:
sudo apt install -y ./google-chrome-stable_current_amd64.deb
From now on you can update your system the way you normally would. Chrome adds a repository to your apt sources.list which will keep your browser updated.