You can change the name using a hex editor;

character name


If you don't already have a hex editor, check out the freeware programs Frhed, XVI32 or those listed here or reviewed on this site.
I use Hackman; the latest 8.x release on the homepage introduces a low file size limit in the freeware version. It is still possible to find the previous 7.x release, though; check here, or search Google for "hack704.zip" or "hack702.zip", etc.