A possibility - If you have ArcGIS 10.2 (or later), there is a handy new tool that allows one to change field names of an existing feature class.
Alter Field (Data Management)
http://resources.arcgis.com/en/help/main/10.2/index.html#//001700000198000000
As always when working with field names, be careful that you adhere to naming conventions and consider what effects the naming will have on downstream uses.
Chris Donohue, GISP