After downloading and editing the file appropriately, you produce a .dvi file with the command:
latex filename.texTo preview the letter, you should convert the .dvi file to a Postscript (.ps) file:
dvips -o filename.ps filename.dvi(If you don't specify the output file with the "-o" option, the output will be sent directly to the printer.)
You can preview the output with ghostview:
ghostview filename.ps