This is a perl script. You need perl, a common tool on UNIX platforms or the unix-like Cygwin under Microsoft Windows.
If you intend to use it on a Unix/Linux platform, the <CTRL>-M characters at the line endings must be removed: Use
dos2unix olgte.pl

The following instructions are for Windows environments

Links for perl:
google for ActivePerl  and choose a distributor of your own choice, e.g. ActiveState.
To get it run on a Windows platform, install perl, open a command window and try

    c:\perl\bin\perl.exe -v

(assuming the default installation path).
The command should print a few lines of installation notes. Then try the more simple

    perl -v

If the simple call works, your PATH system variable has been set correctly. If not, you have DOS editing to do.

You can execute olgte.pl by prepending it with the perl call.
Try (and obtain a short manual page) by
    c:\perl\bin\perl.exe olgte.pl -h
    perl olgte.pl -h
Assume you have received a file  Membach.blq  from the Ocean Loading Provider and stored it in

    C:\dontknow> cd \myloading
    C:\myloading> dir olgt.pl
    yyyy-mm-dd  hh:mm      2 005 olgt.pl
(something like that)

    C:\myloading> perl olgt.pl Membach.blq
    Loading Tide in GRAVITY [m/s^2]:  M2 S2 N2 K2 K1 O1 P1 Q1 Mf Mm Ssa from FES2004
    Station Membach    long.= 6.0063 lat.= 50.6080 height= 0.00  CompCode=FES2004_1S
    M2      :      1.7280e-008          59.09

Look at the first line of olgt.pl  The file you downloaded reads
This is a typical unix path. You can change it to the Windows path
(verify that the program is installed there)

Now you should be able to call the procedure by
C:\myloading> olgt.pl Membach.blq

Good luck!
Hans-Georg Scherneck

APPENDIX: The manual page

            olgte.pl [options] blqfile

          Converts ocean loading gravity parameters
          from Automatic ocean loading provider format
          (a.k.a. BLQ) to TSOFT or, optionally, to ETERNA format.

          Only one file can be processed at one time,
          and the file must be headered, i.e. the complete
          email that http://holt.oso.chalmers.se/loading
          upon a user request must be input.

          This procedure copes with the following BLQ variants:
          One-component    (Gravity only)
          Three-components (Gravity and Tilt)
          um/s**2 or mGal units

 -e  -n   - Extract the tilt information, -e for east, -n for north.
            Default is gravity. -e and -n are mutually exclusive.

 -r       - Reverse sign of amplitudes
 -R       - Reverse sign by adding 180 degrees
            You can specify both -r -R but to no avail

 -s       - Add the "s" before the tide symbol (old tradition)

 -f       - Format ETERNA LOAD-Info in ini-file (ET34-Vxx)

OUTPUT:   Header record 1 contains the component and its units,
          the tide symbols and the name of the ocean model,
          taken from the BLQ input header.

          Header record 2 is issued per site segment of the
          BLQ file and contains
          station name, position, and a CompCode

          The CompCode gives you information about the ocean
          model and whether the post-processor was used
          CompCode examples:
          HAMTIDE_PP = the Hamburg ocean model, post-processed
          SCHW_1S    = the Schwiderski model in one step

          Post processing is applied when stations have been
          located near a coast, else the parameters come from
          the 1-step solution