Yeah try to get him involved, let him feel the baby move and talk to him about what a great big brother he's going to be. I was his age when my kid brother was born, so I got kicked out of the baby slot, but I still thought he was the greatest. On the "birth day" my mom got us big sister and big brother (my older bro was 12) presents, just toys and crafts to keep us entertained during delivery, but we felt really special. I remember seeing him for the first time, and holding him for the first time. Make your little boy a part of the experience, and it can really be fun for him.
wht about gttn him involved wth helping u gt the nursery ready, like small tasks helping u fold some of the babyclthes, the more accustomed he is to the new edition mayb itl b easier, and jus always reassure him tht u love him just the same tht will never change :)
Talk to him, try to understand him, do things he likes even if you don't enjoy it like video games lol. Just bond with him. I recommend the movie 'Courageous' if you havnt already seen it. It's amazing, definitely recommend it to all parents.