You want the Maintenance Manual. If you do not have the CD-ROM documentation, this is the link I use for Avaya documentation:
support.avaya.com/cgi-bin/gx.cgi/AppLogic+elmo
It's a big .pdf document, but I suggest downloading it. It makes it a lot easier to use. Make sure you get the right one, they are different for different software versions (obviously) and there are different ones for different types of PBXs, e.g. G3r or G3si (maybe not so obviously)
Good Luck