Once the new figure has loaded into your viewport it will have replaced the origional figure. In your scene tree you will now be able to open up the figure to manipulate it just like any other figure, but it will not have any textures applied.

(At this point i will assume that people know how to manually apply textures and change surface settings in Daz's "surfaces" tab.... so i won't go into that here...)

Edit your surfaces and apply your texture maps.

At this point you have a choice....

you may either...

1. export a new cr2 with your new figure selected in the scene and create a base figure (at this stage the figure can be loaded and still conformed using the "parameters" tab "fit to" option when loaded into a scene... but will not auto-conform when loaded....

OR
 

2. Load a new copy of the base figure that you used as your parent model (as in step 2.... Do NOT delete the current figure or close the current scene as this will delete your figure and you'll have to start from scratch!).... now you will have your new figure and the origional parent model in the scene together....

Check to make sure that everything is sitting where you wanted it when you made the geometry and then select your new figure in the scene and in the "parameters" tab select the "fit to" option and parent it to the base figure that you made the item for...  when you do this and export the new CR2, your figure will be created as a "conforming figure" that will auto-parent to the origional when loaded...