You can resign the binary using signtool, which is part of the Windows SDK.
The code we use to invoke it is in CommandUtils.cs (look for SignSingleExecutableIfEXEOrDLL); that is hard-coded to work with Epic’s identity but it should give you the information on which command line parameters signtool expects. The rest of the information (copyright/name/etc… in the executable) is set by the .rc file used to link the PE; check out your Resources\Windows\GameName.rc file.
Cheers,
Michael Noland