As discovered by Joel Johnson (via Engadget), the PDF file is supposedly restricted to Apple developers, however it appears the direct link to the schematics can be accessed by the public.
Source: @joeljohnson via Twitter
It should be noted that AppleInsider cannot verify the legitimacy of the blueprints, however the linked webpage has been authenticated by the Entrust Certificate Authority to be owned by Apple.
While the iPhone 5 has seen massive press coverage since its debut on Wednesday, the handset is not yet available to the public and has thus not been subject to a teardown. The blueprints, despite only showing the phone's external attributes, provide the most comprehensive look at the device so far.
New to the iPhone 5 is the rearrangement of the ambient light sensor and front-facing camera, which are now located directly above the ear speaker, and the proximity sensor that takes its place next to the earpiece. Also added is a third microphone seated between the iPhone 5's rebuilt rear-facing camera and LED flash.
Pre-orders for Apple's newest smartphone went live Friday morning, with Apple selling out of initial launch-day supply in an hour. Two of the company's partner carriers, Verizon and AT&T, followed suit some hours later and all are now quoting shipping estimates of two to three weeks. As of this writing, Sprint still has 32GB and 64GB versions available for delivery on Sept. 21.