I also agree with the others. It isn't as simple as we have 25 servers and want to consolidate down to one.. now do it..

You have to find out what each of these do, what usage they have, what is their most stressful time of day.... you might not be able to consolidate them all down to one. YOu also need to look and see if there are any linked servers from one to another. There are a TON of things to highly consider.