CentOS - Feb 2014 - Cange from Samba 3.0 to samba 3 3.6.6

Hi Folks,  I'd like to change from Smaba 3.0.33 to 3.6.6.
Reason: WINDOWS 7 and PDC

Is something to consider when changing (config-Files or so on)?
Have I to uninstall Samba 3.0.33 before or just run an update?

Thx for hints.

Timothy