PIL library is usually delivered as a part of support-sw package. It is however possible to compile it as a standalone package.
After downloading the distribution file, one has to move it to empty directory in which she/he has read and write access rights. Then the following should be done :
gzip -d pil-1.8.2.tar.gz tar xvf pil-1.8.2.tar
First line uncompresses the distribution file, the second unpacks files from tar-file, usually creating several files and subdirectories. Main directory should contain among the others Makefile.in, makeisdc1.in, configure.in, configure files and autoconf subdirectory.