I used the screws (with 3mm washers) to draw the Hurricane nuts into their holes. Some folks apparently use a clamp to push them through. My way worked great, but may be more time consuming than the alternative. I used 8-32 x 1 socket cap screws for the MWs and PRs, and 8-32 x 1 screws with 82 degree heads for the tweeters. I also used 3mm washers for the MWs and PRs. I don't suppose the washers are essential, but I like 'em.
BTW, I got the screws and washers at a local company called Tacoma Screw. They were about 1/10 the price of Lowe's or Home Depot. Shop around.