How to delete unused mount points?

How do I delete these 2 unwanted mount points.

Use sudo rmdir /path/to/mount/point

Mount points are empty directories. In GNU/Linux, all filesystems are mounted in one tree, and Ubuntu is a GNU/Linux. You tried to remove that directory using rmdir command. It's OK. But it said permission denied. It is expected to happen. You are not the owner of neither those directories nor the parent directory, /mnt . You must have superuser permissions to remove those. So use sudo which give root permissions like this:

sudo rmdir /unused/mount/point/

It will prompt for the password. Type your password and hit enter. Your password won't be seen, even not dots. That's normal.