Install macOS High Sierra won't Delete

Solution 1:

Had this issue for a while and stumbled on the solution this morning.

  1. Open Applications folder in Finder
  2. Right Click 'Install macOS *****'
  3. Click on "Show Package Contents"
  4. Click and Drag Contents folder to Trash
  5. Empty Trash
  6. Click and Drag the Application to Trash
  7. Empty Trash

All Gone!