Could this study "totally dismantle" Global Warming claims?
There is several credibility problems with this work.

First, they mention after the title: 


  Abridged Research Report


but I cannot find any related full work from the authors on the matter. As a comparison, in this case, a short, simplified article was prepared as a companion for a full paper. The former is useful for news agencies and general public, and the latter for interested peers.

Second, references are poor. Data sources are cited, from government or agencies FTP sites, which is probably legit (I did not verify the linked data in great detail). GAST dataset are publicly available, as the freedom to publish possible misinterpretation in a proper peer reviewed journal, which remain to be done for the authors actual work.

Third, there is no real methodology. The abridged paper is presenting results and interpretations, but there is no real method.

Fourth, p17


  Clearly the historical GAST data adjustments that have been made have been dramatic and invariably have been favorable to Climate Alarmists’ views regarding Global Warming


This type of statement is having no place in a scientific paper, as this is poorly opinionated based on nothing of substance (Clearly, dramatic, Climate Alarmist) and does not prove much, except that the contribution is not scientific.

Fifth of less importance. the formatting is very poor, which is not helping with the credibility of authors - not that it is very hard to prepare nice and efficient looking reports these days. In a few words, poor communication (in this case, this paper) is not helpful to convince colleagues of alternative ideas (or any ideas).

Sixth until this work reach the stage of being published by an independent peer reviewed medium, I don't see how this could even begin to be a 'threat' to current climate science.