Thanks for posting this guide, although I had uninstalled the KB3035583 before I found your site, an obvious method of removing the Win 10 upgrade. BUT I was not aware of the GWX folder in the System32 folder, thanks for that!
After I had initially allowed KB3035583 to be installed, I noticed the time it took for Windows to cold boot increased substantially. After the desktop appeared, it seemed (was) unresponsive for ~one minute. That is, clicking on a program would result in apparently nothing happening, and after the interval I mentioned, the program's UI would appear. That behavior was unknown prior to installing this update. The PC uses a Z97 mother board, an Intel Xeon E3 v3 processor, a Samsung SM951 OS drive, running Win 8.1 in UEFI booting mode.
After removing KB3035583, the delay in Windows booting and unresponsive desktop has disappeared. I don't recall reading in the comment of this and the Update for Windows 7 and 8.1 silently installs Windows 10 downloader article, about others experiencing this. I may be jumping the gun on the "fix" I think occurred, or did anyone experience a similar thing?
If you think my delay in Windows startup caused by KB3035583 theory is correct, what is happening during that time? The config.xml script running, and communicating with the MS servers? I was in the Reservation phase when I removed KB3035583.
I hope this comment does not earn myself a tinfoil hat...