Migration from ZCS Network edition 32 bit to ZCS Open source 64 bit

[reallove]

Hello,
I am planning to migrate our corporate Zimbra network edition, running on a 32 bit architecture, into a 64 bit server, using the Open source edition.
Are there any special steps to consider during the process ?
Basically, what I am thinking to do is ( ZCS latest versions are already installed on both server, one NE and one OSE ).
1. stop Zimbra on old server
2. update DNS, change hostname on new one
3. transfer /opt/zimbra from old into new server
4. re-run install.sh on new machine

Is there anything else, considering this move ?
Thank you very much !