SAZ file is actually a plain ZIP file (only the extension has been renamed).
So you can use fiddler to capture and save the transaction in SAZ file.
Then rename the file to ZIP extension.Let's say the POST to login.fcc is captured in line number 15 in the fiddler.
Use file explorer and double click on the renamed ZIP file and you will see the following structure.
<Please see attached file for image>
Navigate into "raw" folder.
You will find following file for the line number 15 in the fiddler trace.
015_c.txt -> This is client sent request headers
015_m.xml -> This contains additional information about this transaction.
015_s.txt -> This is server sent response headers
You will need to manually modify 015_c.txt file using notepad.
You can find the "PASSWORD=password01" in the POSTDATA above.
Replace the password01 to ****** and save.
Rename the ZIP extension to SAZ and upload.