I would like to use MnSymbol alongside Springer's LNCS class file, llncs.cls, which can be found in this zip file and in many other places on the web.
\documentclass{llncs}
\usepackage{MnSymbol}
\begin{document}
\end{document}
I get the dreaded ! LaTeX Error: Command\vec' already defined.`
What's the cleanest, simplest way to undefine the \vec introduced by llncs.cls so that I can \usepackage{MnSymbol}?

\let\vec\relaxbefore the usepackage – David Carlisle Feb 12 '14 at 13:58