Contango Theme date box & author section

Hi. I am using Contango theme & would like to change 2 things:

1) The post’s date box (left side of the post’s title) – I would like the change the shape from square to round.

2) How can I remove ‘written by’ section underneath the post’s title? It shows “By: my name”

I am fairly new to WordPress & not very CSS savvy. Any help would be great. Thanks!