@WiiHoney , your advice was very helpful. However, I STILL ran into issues installing MenuHax, and these steps helped me: https://www.reddit.com/r/3dshacks/comments/5c24aj/miniguide_using_menuhax_22_for_downgrading_92105/
I too was on O3DS 10.3.0-6U and getting the am:u handle error in...