Hi Jason, well if you have just done the chamfer you can use undo to remove it.

If you are opening up an older file that you have saved, it is not easy to remove it, but it is possible by breaking the object up into separate surfaces using Edit/Separate, and then removing some of the trimming boundaries, there is an example of this kind of editing in the object repair tutorial here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

If you want to post your model I can help you to do this process on it.

Currently MoI's history function is not able to be applied to chamfer or fillet operations, but I do want to improve this to make these easier to edit.

- Michael