How do I change a user shell type in linux?

[amurleopard]

Also see:
usermod(8) - modify a user account

For instance if you wanted to change the user's shell type from /bin/bash to /bin/zsh

$ sudo usermod -s /bin/zsh testuser

If the shell is already /bin/zsh, it reports there's nothing to change.

$ sudo usermod -s /bin/zsh testuser
usermod: no changes