First head on over to http://bluestacks.com and download their emulator
There are a bunch of different emulators you can use to play mobile games,but i like this one the best.
Once downloaded go through the steps of installing,then find black mobile desert mobile and install it. login to BDM and thats it for the most part. More advanced users can set different keybinds and also set macros(careful though some macros can get you banned). I suggest just going through it and familiarize yourself with the program.
If you really want to get hardcore then you go run this on your pc,download another program to login into it remotely while at school or work and just farm 24/7