To start off with, SAVE. If you don't already have plenty of resources, press "~" to open up the console command menu. Next type "player.additem 000731A4 999", this is the resource for steel. We're going to make steel balls and it takes 5 Steel to make one ball, hence 999 of steel.
Once you got that taken care of, next pull up the workshop menu and look for a Builder. It would be under Power > Manufacturing > Machinery. Build that, but it requires 8 power to operate so either build three small generators or the fusion core generator. Dealer's choice.
When you have that all completed, dump all the steel into the Builder and wait for about 10 - 15 minutes for the achievement to unlock. If you want, you could setup another Builder to make faster progress. Again, dealer's choice. When done, LOAD up your SAVE if you want or continue on.
Any questions and/or concerns, leave a friendly comment.