The easiest way, I imagine, would be to suck the WUs out of the queue with the CLi and the -stop_after_xfer option. Then you could send them zipfiles of all the .SAH files except your user_info.sah.
Somebody who knows SETI Driver, please, check me on the following:
If you're sending several WUs, I believe you could put them all in numbered directories (1, 2, 3, ...) and have your friends install setidriver. Then it should detect and process all the WUs. They might have to put their own user_info.sah in each directory, though; I'm not sure.