How to subtract negative keywords from an Ad campaign?

[lata21]

Choose Your Keywords Carefully.
Sign in to your AdWords account.
Click the Campaigns tab.
Click Shared library link in the left navigation bar.
Click Campaign negative keywords and then the name of the list that you'd like to modify.
You'll see your negative keyword list. You can: Click + Add to add a new keyword.

I didn't understand what do you mean by library link.