Unzipping the archive will produce the the main executables and associated DLLs, plus a subdirectory called "docs", which contains all the documentation for the routines. Using a web browser, read the file "DocIndex.html" in the docs directory in order to access the documentation. You will be prompted to provide a directory into which the TC package and accompanying documentation will be placed.
The TC codes may be executed by simply typing the name of the routine at a command prompt while in the directory containing the routine. The directory containing the TC codes can also be added to ones PATH environment variable, which will permit the routines to be executed from any directory simply by typing the name of the routine.
See the documentation for the individual routines for specific instructions on how to use the terrain correction codes.