Welcome to the forums
As mtorres has said if you would be so kind as to update
your profile with the output of the following that would be great

Code:
su - zimbra
zmcontrol -v
In essence though the upgrade steps are pretty straight forward :-
1) Shutdown ZCS
2) Take a backup
3) Repeat step 2
4) Download the correct version of ZCS and untar
5) As root run install.sh
6) Once 5 has completed check all is functioning okay
7) Perform step 1,2 and 3 again