I am new to the forum this being my first post.

I have recently purchased a post ban Colt MT 6400C (M4).  Of course, being a post-ban weapon it has a compensator in lieu of the typical pre-ban bird cage flash suppressor which is pinned in place.  In addition, the stock is pinned in the full open position.  

My question is this. Now that the sun has set on the so called Assault Weapon law, can I legally modify my post ban MT 6400C to a pre-ban condition?  Thanks in advance.  

yes.