Updating the body shape at run time

Hey everyone,
Is there a way to update the body shape dynamically at runtime. I just have simple box body and it needs to be adjusted to the bounding box of the threeJS body during animation. So far I have tried this method but its not working for me or I may have implemented it wrong.

https://github.com/schteppe/cannon.js/issues/122
https://github.com/schteppe/cannon.js/issues/117

Is there a way to adjust the box shape?

thank you.