How do I change UID of 0 from non-root user?

Question

I have set the UID of user01 to be 0 when I created it. Now I am trying to delete the user and it complains "user01 is currently logged in". I check the process list, and that doesn't seem to be true. However, root (which also has UID of 0) has processes running. How can I delete user01? I also tried changing UID of user01 with usermod, with no luck.

Answer 1

I would do that with:

sed -i '/user01/d' {passwd,shadow}