This thread started regarding DVDs/CDs.
Those you simply call on the phone and order: 800.for.merc
The same information is available via paid subscription, which is where you are. And rather than having the information on CD/DVD, you can print it out from this resource and if you have a PDF writer software, save it to files. This method is the most updated, although of course there is not much updating as regards the older cars.
As for FREE, the only thing that's free is
access to the spare parts system, i.e. EPC. That's at
http://epc.startekinfo.com
NOBODY gives away access to service procedures ... unless they're doing so illegally.