打开Google Play。 点击左上角的☰按钮。 点击我的应用和游戏。 向下滚动更新部分，以找到Messenger。 点击Messenger。 点击更新按钮。 等待更新完成安装。 启动Messenger。 如果无法更新，先卸载再重新安装。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
You'll find this in your Apps list. The icon looks like a shopping bag with the Google Play logo on it.   Be aware that you may have multiple apps called Messenger installed (Google has a separate Messenger app). Look for "Facebook" underneath the app name. If Messenger is not listed in the Updates section, there is no update available for your device. This will open the app's store page. The update will begin downloading, unless you are currently downloading other updates. If this is the case,