I am in the exact same situation. And to make it more complicated you really need to do it in the 1st 90 days. You get 90 days on your 1 year visa when you enter. So before that 90 days runs out you need to either get your extension of stay completed or do border runs every 90 days and do your extension at the end of the 1st. year.
I received my visa based on marriage in America before coming over. And because of the whole 90 day issue I converted it to a visa based on retirement once I was here. Main difference is amount of money you need in the bank. 800k vs. 400k.