I guess there are a couple ways he could do this:

-upload the pdf to the server, then make a link to the file. When the customer clicks the link, they will download the file. BUT I would recommend an EZ-Page that would explain what to do with the order form and a "Download Order Form Here" button, linked to the file. When they click the button, they will begin downloading it.

-Or if this form is something that should be included in a purchase, he could create a new product for the the form, set it to free, and create a download for that order. I think this would allow the form to be downloaded once the customer goes through checkout, but I'm not 100% sure.

I would prefer the EZ-Pages link to order form info and download button.

=)