How to use combination of google fonts in offline mode

Question

I am using google fonts in my webpage by using the link :

https://fonts.googleapis.com/css?family=Open+Sans:300,300i,400,400i,600,600i,700,700i|Nunito:300,300i,400,400i,600,600i,700,700i|Poppins:300,300i,400,400i,500,500i,600,600i,700,700i"

Now I need to run my website over intranet where open internet does not exists. How can I download this font combination and use it offline please.

for single font solution is right here at : Downloading a Google font and setting up an offline site that uses it

but for combination of fonts I could not find any solution yet.