purchased me a post ban bushmaster dissipator. and have purchased also from bushmaster a postban mini y compensator for my rifle. the factory suggest that i have a gun smith install the mini y comp. due to the fact that it is press fit and it requires drilling for a taper pin. Is there anyone out there who has done this without a gunsmith and would like to share any pointers. Two questions i have is, can you press fit the comp onto the barrel without removing the upper reciever and second, when drilling for the taper pin how is this accomplished drilling at an angle on the barrel.......thanks