Make it a box set with a book for players and one for DMs, extra book for an adventure and maybe the beginnings of a new gameworld and then go from there. Everything explained clearly and step by step like the original Red Box Basic, and with enough material to get a few games. Let the players get up to about level 10 and everything else is modular. So, drop the three book format, stick it in a pleasant shrink-wrapped box that would look nice on a toy store shelf and make it accessible to fresh gaming blood.
Most of all, pull back the design. Drop the stylised anime batshit insane impractical armour and weapons and try and make it a bit more grounded in reality. Release books for gameworlds, the usual Forgotten Realms and that kind of thing. Go from there.
So, after those changes, the character sheet would look something like this: