Question: how to install dmg file in macbook?
Answer: Locate the file. After you have downloaded the file, check the location where you downloaded it and find the DMG file itself. ... 
Open the file. Double-click the file to open it, and you should see it mount and display as if you plugged in an external drive or inserted a CD-ROM. ... 
Install the application. ... 
Eject the DMG file.