To use Apt fast, you will first require installing Axel, which can be installed from the following Terminal command:
sudo apt-get install axel
Once done, install Apt fast by entering the following commands in the Terminal.
sudo add-apt-repository ppa:tldm217/tahutek.net
sudo apt-get update
sudo apt-get install apt-fast
After Apt fast is installed, replace apt-get with apt-fast commands for an accelerated download speed.
You can also check out the alternative installation method for Apt fast from the developer’s website here and download the .Sh file from the download link given below. However, I found the above mentioned method to be quite easy and hassle free.