The Facebook Messenger app has a blue and white chat bubble icon with a lightning bolt inside. You'll find it either on the home screen or in the app drawer. If you don't have Facebook Messenger, you'll need to install it from the App Store (iPhone/iPad) or Play Store (Android). It looks like a pencil (and a sheet of paper, if using an iPhone or iPad) and it appears at the top-right corner of Messenger. You can scroll down and tap both friends in the list, or search for your friends using the "Search" bar at the top of the screen. Just make sure you've selected only the two friends you wish to connect. This adds both friends to the "To" field at the top of the message. To start typing, tap the blank typing area at the bottom of the message. You could say something like, "Just sending a message to connect you two!" if you wish. The Send button may appear as a paper airplane icon or an arrow, depending on the platform and version. This creates a group message. Any messages you (or your two friends) type in response will be delivered to all members of the group. If you don't want to be a part of the conversation between your two friends, you have the option to remove yourself. Just tap the names of the people you're communicating with at the top of the chat and select Leave Chat (iPhone/iPad) or Leave Group (Android).

How would you rephrase that briefly using Vietnamese?
Mở Facebook Messenger trên điện thoại hoặc máy tính bảng. Chạm vào biểu tượng tin nhắn mới. Chọn hai người mà bạn muốn giới thiệu. Viết một tin nhắn để giới thiệu họ. Chạm vào nút Send (Gửi). Rời khỏi cuộc trò chuyện (tùy chọn).