Sorry if this is old news.
Most of you probably know that your Soldier ID is linked to your Origin ID and cannot be changed. That means if you made your Origin Login name something stupid like "xXMilky_goatnipples420Xx" that will be your Soldier's ID in-game. And you can never change it.
But wait. You can!
First download EA's Scrabble app on your Android or iOS device. Yeah, Scrabble, the crossword game.
Log in to your origin account within the app
Click on the Gear icon (was in the lower left on the Android version) and update your Origin details.
Voila! You now have a new Origin ID. Note: If your name is already taken it will give you an error message. Now you can finally make your name way cooler like "SSJ_TreeBlazer_666<(*_*)>!"
Disclaimer: I am not responsible if this fucks up your shit. I already did this and changed my Origin ID successfully. If it doesn't work for you I don't know why.