Change \contentsname in Book(KOMA-Script)

[Waluyo Adi Siswanto]

I would like to change the \contentsname in Book(KOMA-Script)
I tried to insert in the LaTeX preamble (Document>Settings)

\renewcommand{\contentsname}{Newname}

also
\AtBeginDocument{\renewcommand{\contentsname}{Newname}}

Both did not work.
It works if I insert the LaTeX command (the first one) in the
document, but it does not look clean.

Thanks
WAS