Citrix Farm Configuration

I need to know what I have to do to rebuild the data collector in my 6 server farm. I am running a mixed environment trying to rebuild everything so that I have clean installations of Windows 2003 and PS 4.5 on all 6 servers. My data collector is still running PS 4.0 and that is the last server that I have to rebuild. I am not upgrading anything but I am joining the original farm.

Is there anything specific that I have to do so that I don’t make the farm inoperable?