Here’s what you’ll be working your way towards:

A shiny new icon for your MiniDrive.

Here’s how:

  1. Right / secondary click on MiniDrive, either the icon on your desktop or Finder > Devices > MiniDrive.
  2. Select ‘Get Info’.
  3. Ignore the obvious: mucking about with the big preview icon leads to naught but madness.
  4. Find the tiny icon in the top left. This shall now be known as The Target.
  5. Drag your .icns file from wherever you’ve saved it onto The Target.
  6. You may need a restart for the changes to take effect.