Git repo for http://www.vim.org/scripts/script.php?script_id=1721
https://github.com/qpkorr/vim-renamer is the official github repo for the renamer.vim script on vim.org, and supercedes the above location.
The repo contains the files suitable for a vim pathogen "bundle" directory (google is your friend).
From renamer.txt, the help file:
Show a list of file names in a directory, rename then in the vim buffer using vim editing commands, then have vim rename them on disk
Renaming a single file is easily done via an operating system file explorer, the vim file explorer (netrw.vim), or the command line. When you want to rename a bunch of files, especially when you want to do a common text manipulation to those file names, this plugin may help. It shows you all the files in the current directory (and optionally in those below it), and lets you edit their names in the vim buffer. When you're ready, issue the command ":Ren" to perform the mass rename. Relative paths can be given, and new directories will be created, with 755 permissions, as required.
Use the Renamer command invoke the functionality and set the User Configurable Variables defined in plugin/renamer.vim as desired.
The usual pathogen setup - add renamer directory to $HOME/.vim/bundle directory.
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More details in the full renamer.txt file.