The tar command unpacks the .tar file and recreates its component files, directory structure and all, on your disk. These are normally shell files. Uncompress and unshell everything. At this point you have to know enough to repair the makefile or kludge around it's problems. Not a fun task, but something that must be done.
Some programs are better than others, so good luck and happy hunting.
This tutorial was originally created by Marshall Brain for students at North Carolina State University. Marshall Brain is the Director of Programmer Training at Interface Technologies, a firm specializing in programmer training and based in Wake Forest, North Carolina. He is the author of five books on Motif, Windows and Windows NT programming.