Actually not sure if this first one works all the time.
Long Path Tool: Path Too Long | Filename too long | Filename is too long | Path too long utility.
The is the only tool I’ve used that has almost always worked for me. Every other solution I’ve read up on doing so from within Windows has failed me more than a few times.
http://myprogramspace.blogspot.com.au/2008/07/krename-multi-file-rename-tool-v0.html