Empty the Trash with files in use

Problem

When you empty the Trash on your Mac, you get the following error:
“The operation can’t be completed because the item <filename> is in use.”

Cause

Any files mentioned with the error above are still being used by the system.

Solution

1. Click the Finder icon in the dock (smiley face icon).
2. On the top menu, click Finder.
3. Click Secure Empty Trash.
4. Click the “Secure Empty Trash” button.