Just a simple bash script to batch rename files: takes one or two strings as arguments, and removes or replaces all instances of that string from within all filenames in the specified directory.

replaceFilenameString.sh

# /bin/sh
#
# Replaces a string from all filenames in the sourcedir.
# If the second argument is empty, it will simply remove the string.

sourcedir="."
stringToChange="$1"
replacementString="$2"

cd "$sourcedir"
for f in *"$1"*; do
        mv "$f" "${f/$stringToChange/$replacementString}";
done