Yeah, he tried so hard that it went on for 22 months. You are full of shit. The only thing you have is McGahn's recollection of the conversation vs. Trump's. You are desperately clinging to McGahn's version because you think it helps the case you so desperately clung to. Again... if he was truly adamant about shutting it down... why didn't he?
Even if Trump specifically asked for McGahn to get Rosenstein to fire Mueller, that is a discussion Trump can have. McGahn was his counsel. If McGahn resigning made Trump realize he couldn't do it or if subsequent counsel convinced him not to, the point is that Trump did not get Mueller fired.
Has Trump offered anything that contradicts McGahn? No, ordering your attorney to carry out an illegal does not absolve you of a crime. Neither does being unsuccessful, or later changing your mind. Keep throwing shit on the wall, it ain’t sticking.