Requirements:
1.) Enter your root wordpress directory.
2.)Download the latest wordpress.zip to it.
#backup your current files just in case
cp -a . wp-current-bk`date +%Y%m%d`
unzip wordpress-3.7.1.zip
rm -rf wp-includes
rm -rf wp-admin
echo y|cp -a wordpress/wp-includes .
echo y|cp -a wordpress/wp-admin .
echo y|cp -a wordpress/wp-content/* wp-content
echo y|cp wordpress/* .........