|Without a little more information, we cannot possibly help you.|
What exactly are you trying to update? The SW/FW on the network appliances? The network appliances themselves The OS's on the PC's? The PC hardware? Or are you perhaps looking at going from copper to fiber?
Once we know what it is you're trying to accomplish, then we can (hopefully) help you out.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.