howq do delete old chat buddys?

[Dennis]

there is a box on the right side of my screen it has a name at the top of ythe box. a person i used to chat with how do i delete orv change that name i do'nt know how itbeven got there i need some help aqs this site dosen't have a customer help phone number at least i havn't found one can any body outv there help me please thank in advance