You can edit the params files or you can add the option in your command line. I do the latter on a continual basis with my scripts. Just add "tasks.sqrt.threads=4" within the command:
Code:
./cado-nfs.py <comp> . . . tasks.sqrt.threads=4 . . .
I pull the spaces around the "=" out when I add an option to the command line, but I probably don't need to. Options added to the command line will show up in the snapshots.