In this manual it says to edit the FreeSurferDefs.csh file and change the following line where specified: setenv CSURF_DIR XXXXXXXX # CHANGE_THIS_DEFINITION and then type 'csurf' on the prompt to run the software.
Those instructions are out of date, sorry. We're (still) revamping our documentation for the next release. You should use the instructions in the INSTALL file, also here at:
ftp://surfer.nmr.mgh.harvard.edu/pub/docs/INSTALL
Note that for the Darwin version, you may also need to install a few things with fink like libjpeg and libtiff. Feel free to email me with questions on the Darwin installation, I know it's a pain.