Rearrange Comment Block Items

I am modifying the comment block to work as a messaging system. Functionally it’s working great, but I’m looking for some advice on the best way to rearrange the comment block for better viewing. I’d like to…

  1. Switch the two section below.
  2. Reverse the order of the comments, so that the most recent appear at the bottom.

Is this feasible? Where would be the best place to learn how to make this happen?

Thank you!