You do that by having enough people that were nearby, or better, involved in the overall conspiracy testifying that they were operating with the knowledge that what they were doing was illegal.

“Beyond a reasonable doubt” is not “beyond the shadow of any doubt.”

If you have three or four insiders saying that Trump wanted to do X (which was an illegal act), and corroborating testimony that he was told by these lawyers, like Ellis, that the law doesn’t work that way, that this is illegal, it’s not reasonable that Trump can righteously still believe he was not committing a crime. By that point it’s “ignorance of the law” at best, which is not a defense.

Testimonies will be catered to pointing this out, and there will be plenty of arguments about the intent of text messages and emails and conversations surrounding Trump, they will ultimately establish everyone was aware that this illegal obstruction is being done knowingly and at Trump’s direction. Once you’re there, it requires an absolutely unreasonable juror to conclude he had any reason to believe be was in the right.