There were quit a few articles on the 25th Anniversary back in 2012, but this article by Motherboard went into a lot more technical detail about how this was probably pulled off:
Indeed, the current link seems to just be Atlas Obscura engaging in some churnalism and regurgitating existing articles on the subject. Apropos of not much, the account that posted the current link a) is new, and b) has posted nothing but Atlas Obscura links thus far.
I also find it a bit strange that Atlas Obscura is even posting this, being that its modus operandi is stated as being "the definitive guide to the world's wondrous and curious places." Signal intrusion or the 80s aren't much of a "place" no matter how curious they are.
http://motherboard.vice.com/read/headroom-hacker
It also details other TV intrusions as well.