So for anybody looking to change or at least alter their username, good news! SB Nation has made it so that you get one easy name change.
You can read the instructions here. Basically, you go to your account via the link in the top-right. From there, at the drop-down menu under your profile picture, you choose "Edit Account and Settings". The first option should then be to use your one free username change.
If you want a subsequent change, you can still follow the old procedure of emailing email@example.com and giving your rationale for getting a change. The thing is that with the new "one change" feature, I'm guessing they will be much more strict on providing name changes. So use your one change wisely!
Or be like me, and rashly use it on removing the underscore from your name, and then hope you never have a change of heart in the future.