Very simple on the back of the EGR pipe where it mates up with the down pipe there is two nuts. get some good heat on the nuts and loosen then slip in the blocker plate and tighten back up. you can also check on Kennedy Diesels web site I believe he has a set of install instructions on his site.
Make sure you have a programmer that will override the Check engine light that will come up on you after install.
Im new to the duramax world ive always had a powerstroke but i traded it for an 06 lbz and im running efi live, and my truck has thrown the egr code twice now, a little insight? What does the blocker do?