I am unable to empty two items in Trash
There are two folders in Trash that won't empty. The error message says they are in use. Two are folders, and the other two items are referred to as "share" and "usr". I have followed every suggestion I can find in various discussion groups, and nothing works so far.
I also tried to start my MacPro in Safe Mode, but was unsuccessful. Despite holding the Shift key down until the sign-in page appeared, the boot is always shown as "normal".
Mac Pro (Late 2013), macOS High Sierra (10.13.4)