First of all you need to install it using Package Manager console as below:-
It will log message that the bootstap is successfully added
Now we need to include the bootstrap css file to the MVC view so that it can be applied when view it rendered on browser. I am including it on bundleconfig.cs file as below.
Now go to the view page(cshtml or vbhtml) where you want to apply some of the default css on the link to make it look like button and update it as below.
Run the MVC project and go to the view , it will display the link as below
Hope you find this post useful. Thanks for reading.