You'd do better by running a tool like CCleaner, or the cleanup tool that comes bundled with Windows.
But quite frankly, with how cheap storage is these days, you should never have this problem. Just install additional/larger drives.
As OP above says - do not try to delete your cache. It's not a temporary storage. You'll negatively impact your client's performance while the files are downloaded again, and you'll just end up in the same situation.
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As already stated, it's not recommended to do this regularly unless you're having major issues. If it's just disk space you're worrying about, you can delete the cache on your local machine and install it on an external drive: Installing the cache a second hard drive -- That'll be +5GB space freed .
As for everything else, typically, you don't need install any software to free some space. If you're using a Windows OS, just open the File Explorer, right-click on "Local Disk (C" and select "Disk Cleanup". This will calculate how much files will be removed such as Temporary Files, Windows Update cleanup, Restore points, etc. This will take a long process depending on how much space is on your drive, so I'd probably dedicate 1 day to do this.