All you're doing with that is filling in the form and then it will generate a PDF for you to print. You're not renewing online; you're filling out the form while online.
If you have a post office that does renewals, go there and grab the paper form.
. And I cannot imagine why it would take that long to fill it out. Go here (
https://travel.state.gov/content/passports/en/passports/renew.html), look over under the yellow Forms box, and click PDF to print it out if you don't have a nearby office to grab a form from.
As for who can renew by mail (because that's what you're doing even if you fill it out online)...