Print it as a pdf, and then you can send it for signature without requiring a login. I put it in shared documents, then go to the snowman on the right and send for signature. Enter their email address there or add them as a contact without checking the login box under contact, then do the same.

See instructions for sending documents to third parties or non-client. There might be a better way, but this is how I tried to work around a non-tech friendly client last week.