tar usage and delete/create username

Linux and Unix-Like Linux
1

dear Linux expert,
I am using Fedora R5

how to use tar to archive /var to a test_var.tar and compressing it?
how to delete a user? just remove the line in /etc/passwd?
and then what is the procedure to create a new user ?

many thank

2

become root :

  1. tar cf test_var.tar /var
  2. userdel
  3. useradd
3

1a. tar cjf test_var.tar /var
1b. tar czf test_var.tar /var

For bzip2 or gzip compression respectively.