(Note: -tr s tells TEQC the input is a Trimble file. You must know your receiver format.)
Since TEQC is a command-line tool, you must run it via the Command Prompt (Windows) or Terminal (Mac/Linux). rinex converter 5.0 8 download
You're looking for information on RINEX Converter 5.0.8 and where to download it. Here's what I found: (Note: -tr s tells TEQC the input is a Trimble file
Before downloading and installing RINEX Converter 5.0.8, ensure your system meets the minimum requirements: rinex converter 5.0 8 download