See this Stack Overflow question for the source of this file. I've successfully used this a project but use at your own risk.
##Step 1: Add entries to "rename_classes.txt" file where each line contains a class name from/to pair separated by one or more tabs. Example:
MyClassA ZZMyClassA
MyClassB ZZMyClassB
MyClassC ZZMyClassC
##Step #2: Copy and paste both files into the project directory, and run the shell script.
Notes:
- This script will update all references to classes found in the Project File, XIB files, storyboard files, .h & .m source files.
- For each modified file, a backup file with the original contents will be created named "[filename].bak".
- This script only renames .h & .m files. .xib files and Storyboards will need to be renamed by hand.
- 'PROJECT_DIR' can be set to another directory if desired.
- 'RENAME_CLASSES' should point to the file created in Step #1.