Unless things have changed since I was there last, anyone can register and purchase a "subscription". On the log-in page, below the e-mail/password fill-in windows, click on "Purchase and create subscription". Subscriptions are available for various lengths of time. The 72 hour subscription should be enough to download the service manual and other documentation. The service manuals are made up of a large number of small pdf files (could run over 1000 now with all the new electronic options), each covering an individual function or operation. The site limits downloads to 50/hour, so it could take a fair number of hours, overall, to retrieve all the files. There's no official site that provides the full service manual in one file. There's a "users guide" -- click on link at the top right of the log-in page.
There's threads here related to other sources of service manuals -- a search should lead to them.
Incidentally, Mitchells and Alldata, and perhaps others, that specialize in technical documentation support for shops and professionals, also have subscription plans for DIYers. These are on-line services, but allow downloading and printing of pages. They are reasonably priced (last time I looked, 4 or 5 year subscriptions were priced at around $50), and are usually up-to-date with revisions, TSBs, recalls etc. Some public libraries have subscriptions to these services for use by members, which could be good way to get an idea of what they're like and how to use the web-based data. They might be an alternative to downloading from the SOA site, and then having to deal with service manual updates, which often occur in the first year or two.