[Samba] How do update samba on Ubuntu

[Lucia Donatto]

Hi all, I´ve got an ubuntu 8.04 server with samba 3.0.28 and ldap installed
in a net that is working ok.
I´d like to actualize samba to the actual version and don´t know how.
Sudo apt-get upgrade will do?
I´ve read in internet that some people uninstall it and it really scares me!
If someone have any idea about how to do it and can give me a link or some
clue about it, I really will apreciate it!

Thank you very much for your time.