I have a model in CC3. She looks great, but has elf-live ears. Can I modify her ears without getting into problems? If so, how should I proceed?
Thanks always,
Frank

Actually, you are in trouble :). There is no easy method for swapping *non-conventional* parts (parts other than heads, eyes, teeth) of the CC body.

You can sculpt elf ears down of course (not in CC though) but you have to be a master of sculpting to do that.
Some third party apps might have tools for swapping parts without disrupting poly count and vertex order (which is a main obstacle for importing characters/morphs back into CC).
I personally use Blender with Mesh Data Transfer add-on (https://forum.reallusion.com/482754/Mesh-Data-Transfer-Addon) for swapping body parts, and I think I master it to level where I can swap anything between any CC character.

If you have some experience with Blender, let me know and I'll put together a quick tut for swapping ears fairly easy.

Couple ideas to get rid of 'em.

First check in the favorites section at the top of the morph list. If there happens to be a elf ears slider there, set it to zero.
If there are no elf ear sliders, then it has been baked. So if you happen to have Ultimate Morphs, try adding the elf ear slider, and then type "-100" into the number box at the right-end of the slider.
Or just add a new head preset from your content library.

Thanks for the instructions. One of the things I've loved about Reallusion is that it's relatively a inexpensive and pretty easy solution to get into 3D modeling. Kudos to 4u2ges and Rampa for the guidance. I will definitely try Ultimate Morphs first. However, many of newbies would benefit from a short tutorial from you, 4u2ges, even if it's slightly outside of CC3. Blender is a good and inexpensive place to look for answers. Again, thank you both very much. 

There, I have put together a quick tut: https://forum.reallusion.com/FindPost486003.aspx
Hope this helps.