I'm quite nub in web development, so be gentle please. If this place is wrong for such problems point me to a more appropriate resource please.
To became more familiar with web-programming I found good (as I thought) area for self-improvement. One of my friends owns web project. This project was developed during last 15 years with one programmer who seems to be slightly tired and probably is needed for backup. I've tried (for the very beginning) copy all stuff to the new development environment and found that project consists of several tens of sites: site1.domain.name, site2.domain.name, etc. So the problem that sources contains about million hrefs to the absolute addresses. So I need any advices how to reorganize this project to make it more convenient like project.anotherdomain.name/site1 or any other approaches to moving project to the development environment. Project is mostly in PHP+mysql, so I'm affraid that db also can contain absolute addresses.