There's a tutorial or two out there as well, which show what can be done for posed figures, rather than animations. There's several tricks which can be used. Start with just conforming the clothing to the new figure. 1: make use of all the morphs the clothing might have. 2: It may be possible to make some parts of the figure invisible. For instance, the P5 combat pants will fit, but the inside of the P4 figures thighs will show through. So make the thigh invisible. 3: Consider what can be done in post production. Make the chest invisible, and you have a nasty hole. Well, do two renders, with and without, put them in seperate layers in Photoshop or whatever, and fake it. Actually converting clothes for full posing and animation is much more difficult. The clothes need to match both the shape and the underlying structure of the body. There's no easy answers.