You can't install a theme natively for Bluestacks in hope of changing the interface. You will have to install a launcher and then apply a theme to that launcher and the only Hip Hop theme available is for CM Launcher.
Use the Search feature available within the software and search for CM Launcher and then do the same and search for Hip Hop Theme.
Note: If you use the same account on web and in Bluestacks, then you can use the web to directly install apps into Bluestacks.
