First you need to
1) Organise world peace and achieve stability at all borders
2) Find out a way of convincing leaders of all countries that there is not going to be any more war against their country.
May I suggest that you start by campaigning for withdrawal of US troops from Afghanistan and Iraq. As an American voter and citizen that's an area where you might be able to make a small difference. Next, campaign for the US withdraw it's bases from places like Korea and Europe. Next, try to find a solution to the Israel question... Putting missiles anywhere along the border of Russia is definitely not a good way to make them feel that it's safe to reduce the army. But right now that is what the US is proposing.
If you can tackle all those problems. then after that you can raise the question of dropping conscription again.