First I need to declare that I am not a teacher, as the rules of this forum require.
Second, coming to the sentence you asked about, I think the reason "change" is used instead of "changed" is because that, while the sentence in its complete form looks like this:
He didn't do anything less Earth-shattering (pun intended) than completely change the way the universe was viewed.
it may be possible to simplify it into this:
He didn't do... than change...
In other words, I believe the past-tense word "did" has sovereignty over both "do" and "change".
Hope I have expressed myself clearly enough. There is no guarantee that my understanding of the issue is correct, though.
Student or Learner