I've done a previous pair of tutorials on keeping bones when converting items between figures, as for instance between Genesis and Genesis 2.  That method takes a few steps and an obj export/import.  This way is faster, although it doesn't work well with Generation 4 conversion.

You will need:

-The figure you want to convert TO.
-The piece of clothing or hair you want to convert.
-Any relevant clones.  For e.g., you will need to purchase the Michael 4 for Genesis 2 Male and/or Victoria 4 for Genesis 2 Female to convert items between Gen 4 and Genesis 2.

Instructions:

Load the figure.

Load the item of clothing.   Cancel Autofit if it is triggered.

Start the Transfer Utility.  Its icon looks like an arrow pointing up and right.

For Scene Item under Source, choose the figure.

For Scene Item under Target, choose the clothing or hair.

Under Source/Item Shape, choose a clone (e.g., the Victoria 4 clone if converting from a V4 item).

Under General Options below, click Weight Maps, and on the right click MERGE HIERARCHIES.  This is what does the magic.

Check Reverse Source Shape from Target as well.

You can choose to add a smoothing/collision modifier or not.  I usually do.  Some Generation 4 items can handle it better than others, but any Genesis or G2 item should be okay.

Click Accept.

Now the item should refit to the figure while retaining not only its morphs, but its bones.  I was able to convert the main pieces of the Dragon Braid in about five minutes this way, although it does still cause the same distortion in the lower shoulder area. 

That one still works because it has morph-based movement.  In general this doesn't work as well with Generation 4 as it does between G1 and either G2, or between the G2's, because with conversion from cr2 to weight mapping it will recreate the bones but not the maps.

Be sure to save back to library with its own folder names.  I used "ConvertedHairsG2F" for all the Dragon Braid pieces.