Its easy if your files are organized. Say you have all your media on the same drive in sub folders under one folder.
If you use the same file structure and drive letters on both computers you will have no problem.
If you use different drive letters or a different master folder; then you wull have to point Pr to the first file. However; if all media is in the same folder; Pr should find all the other files on its own,
IF your current files system is a disorganized mess with media on different drives, differnt folders all over; consider running Project Manger to Collect all your files into one location first. But this is not necessary if you are well organized in the first place.
Have you considered putting the old drives in the new machine?
If the location of these files is maintained, you will be home free. Let's say that they are on E:\ now. If you locate them, with the same structure on the E:\ of the new machine, all is good.
Now, if you cannot locate them in that established location, then PrPro will first prompt you and help you locate them, when you Open the Project. If they are all in the same folder, it will be automatic, once you navigate PrPr to that folder. If they are in different folders, you'll have to help PrPro, by navigating to each of those folders.