The first line will Remove all in that part including the "Summary - (Username)". I can't think anyway to remove only the username. -.-
Second line hides the username in "Name: username"
The last line hides the avatar.
Dude I was also able to do this because Summary - (Username) had Class there(titlebg). Just adding this line to the above script will hide the summary-Second line hides the username in "Name: username"
The last line hides the avatar.
Code:
document.getElementsByClassName("titlebg")[0].style.visibility = "hidden";
But in the case of Name: (Username) there was no class or ID was used or I can't found the way so that is why I also could not solve the problem here. 
