yes, you need to edit the fzp file for the part. You can get that either from the directory Fritzing stored it in or by exporting the part as noted above and either changing the fzpz file extension to .zip and unzipping it or (on windows anyway) use 7zip to unzip it directly. The non video howto posted above describes how to do this (I think both ways, but certainly with 7zip). it will likely have the filename
part.CrampsHat_4e3e9765725e7e3e28ba5cfd2bacd566_1.fzp
when unzipped. How to rezip it after editing is also covered in the howto.