First of all, you should open an internet browser and then go to cricut.com/setup .

After this, you should choose Download option. Then you will find that the screen will change, when the application file is downloaded.

If the download is finished, then double-tap on the .dmg file in the browser or in the Downloads folder.

Now, you should drag the Cricut icon to Applications folder icon to start the installation. Then, you will find that Cricut Design Space for Desktop gets added to your Applications folder.

To launch Design Space for Desktop, you should double-tap on Cricut Design Space in your Applications folder. In order to create a shortcut, you should drag the application to your dock.  ( Via Cricut design space download )

Here, it will ask if you want to open the application which is downloaded from internet. Then, choose Open option to continue.

At last, Sign in with your Cricut ID and password and just enjoy the Design Space for Desktop.