Unmount the target device

The second command detaches the USB stick from our PC, we unmount the USB stick.

The command is printed as:

umount /dev/sd?1

but it must be directed the “address” you find for your target USB stick.

The code above contains a question mark which will not be recognised as part of this command.

Paste the command (complete with ?) into the Terminal, then edit the question mark out of the command and replace it with your drive letter.

To edit a command already pasted into the Terminal use the left arrow key to move the cursor to the left into the text. When the cursor is over the ? press the delete key. Enter the replacement character from the keyboard. Clear the cursor away from the text with the right arrow key. Double check that the command is now correct.