Click the Safari app icon, which resembles a blue compass, in your Mac's Dock at the bottom of the screen. This extension allows you to translate entire webpages. It's to the right of the extension's icon. Doing so will install the extension to Safari. Find and open the webpage that you want to translate into another language. A drop-down menu will appear. Depending on your Mac, you may need to hold down Control while clicking a blank space on the page. It should be in the drop-down menu. Doing so opens a toolbar below the address bar that's at the top of the window. In the toolbar that appears, click the "Language" drop-down box, then click the language you want to use for the translated webpage. It's at the bottom of the toolbar. Doing so will reload your webpage in your selected language.

How would you rephrase that briefly using Vietnamese?
Mở Safari. Mở Translate extension for Safari. Nhấn Install now (Cài đặt ngay). Truy cập trang web bạn muốn dịch. Nhấp chuột phải vào một khoảng trống trên trang. Nhấn Translate this page (Dịch trang này). Chọn một ngôn ngữ. Nhấp vào mũi tên "Translate"  (Dịch).