The models are packed in .A, .B, .C files, to unpack them download the tool created by howfie: https://www.mediafire.com/?9drozatdk9ybi5q, place it where the .A, .B, .C files are and run it.
You'll obtain some folders full of models and Textures!
Now it depends on which game you have used, if you used the first game (One Piece Pirate Warriors 1) you should have .lwo files that are the 3d models, they can be opened with Lightwave;
if you have used the 2nd game you'll have .smc files, they can be opened with the Blender script you've downloaded with the ripper (I know that there are compatibility issues with the script, if you face problems try to use Blender 2.49b).
In both cases the textures and the models of a character will be separated, so you'll have to search for the textures in the folders you have! (you'll find a list of most models and textures position here).
Update I figured out how to extract the skin weights from PW2 thanks to a friend!
After having imported the .smc files in Blender, delete all the models without UV maps, they are the LOD models used ingame, and move to the proper position the misplaced parts (this happens mostly with hairs and boobs!).
After that import the skeleton (it's the .smc file with skel in it's name!) and move it to fit the model, now select all (meshes + skeleton) and hit ctrl+P, a small box will appear, you've to select armature a lot of times until it disappears.
The main part of the work is done, now you can export the model to .fbx and you'll have the skin data attached to it.