GrandPerspective  is an application that analyzes your hard drive and gives you a graphical representation of where all your space has gone. To download and use the application, follow these steps;

1. Open Self Service  and search for GrandPerspective - just "grand" should be fine.
   
    
2. Click Install, and again when prompted.
   
    
3. Once the install has completed, open GrandPerspective from your Applications Folder . Once launched, you’ll get a dialog box asking which folder you’d like to scan. Select your User folder (i.e. Username), then click Scan.
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4. Once the application has finished scanning your User folder, it will display how much space is being used in a graphical format (as seen below). The larger squares indicate where the most space is being used in your Hard Drive (i.e. the biggest chunks are your biggest files). 
   
    
5. If you find something you don't need, you can Right Click the square, then select Reveal in Finder to see the file in your computer. You may then choose to delete it if necessary - Be careful when deleting files. Make sure that you don't erase anything essential to the running of your machine (i.e. system files)​.
   
    

For more information on clearing space within your Hard Drive, visit this FAQ.