This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The same way you would access it anywhere else. But if the List is a private member of another class, and it doesn’t have public getList() or addToList(...) methods, etc., then maybe you ought not to try.