First we download master.dat, master.pro, and es.tar.gz

Then we unzip and extract the tarball:
tar -xvzf es.tar.gz

In IDL, to play with master.pro, one first types:
IDL> .run master.pro
% Compiled module: MASTER.

If one just wants to readin the massive master.dat file, type the following 
to get a structure named "master" with all of the data in master.dat
IDL> master, 'master.dat', master

If one wants "master" and information about a specific star in master.dat, 
plus a plotted reconstruction of the star, input for "starid" an array of 
the mjd, plate, and fiber numbers of the star you want info on and for 
"stardata" any variable name.  The program will return the structure "stardata" 
with all of the data contained in master.dat for that star.
IDL> master, 'master.dat', master, starid=[52203, 685, 129], stardata=stardata

If one wants "master", "stardata", and a variable containing the wavelength 
and reconstructed flux of the specific star, type the following to get 
the structure "spectrum" with tags lambda and flux.
IDL> master, 'master.dat', master, starid=[52203, 685, 129], stardata=stardata, spectrum=spectrum