If there are multiple users, then set up separate accounts (in Preferences) for them that limits their "visibility" and ability to make changes or see certain areas.
Do you want to change then name of the hard drive too or can that remain visible?
If you want to change the appearance of the icon, find a graphic you like and get it into the machine... copy it. Click once on the hard drive and under File, select Get Info. In the get info window, click once on the icon in the upper left corner. Paste the graphic you just copied...
No need to get into Unix - Macs are EASY to use. Simplicity is good.
But before you hide the icon, tell us why you want to hide it... There is no good reason to do so... As a Unix user, you know what account privilege control can provide for...
I attempt to hide the icon Macintosh HD on the user's desktop and in the Finder Window.
Since I just come from UNIX, I attempt to access via a terminal to make the change, but not knowing where to find this icon.
What is the best way to accomplish this task?

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