How to change anspress banner image on user profile page?

I am pretty new to anspress. I notice that there is a default image banner on user profile page, and I have looked around frontend and backend, I have no clue where I can replace with my desired image, can you please help, thanks? I also have a problem with the latest version, all my side widgets appears at below of anspress content instead of right-hand or left-hand side after I upgraded to the version 1.4.