mitmit,
You can change these values by editing the file directly:
physical file path: admin\users\App_LocalResources\User.ascx.resx (examples of values found here are: UserInfo_Username.Text, UserInfo_FirstName.Text, UserInfo_LastName.Text)
or by editing them through the application:
(log in as admin or host) navigate to admin -> languages -> language editor (from context menu) -> Local Resources (from the tree) -> admin -> users -> app_localresources -> user.ascx
hope that helps,
Ian