Simple.

I take it you had zeroed your figure first before you made your new hip.
1-Load your figure.
2-Import your new hip. ( if everything was zeroed first it should line up.)
3-Export your figure without the old hip and with the new hip. ( selections in export herichy file.)As a Wave front object with everything checked in export options except as morph target. With a new name such as V4_New_Hip.
4-Place that new .obj in what ever file you want but as long as you have renamed it. It can go into the same geometery folder as the original figure's.
5-Open the original figures Cr2 with notepad or what ever Cr2 edit app you have. Replace the figure's .obj with the new versions in both/ that is 2 path lines. located at the early stages of the Cr2. You may need to change the path also if you put the new .obj somewhere else.
6-Save the new Cr2 with a new name. Very important step because you don't want to over-write your original Cr2. Not a good thing.

That's it. It should all load and work as the original figure.

If you need more help IM me and I'll walk you though it.