I was trying to delete one of my DA2 characters and I couldn't find where to go to do it...
Usually it's when you switch chars that you got a button to delete a character (like in Mass Effect), but there were none in there...
yeah the best way to do it... is go to the Memory settings in the "My XBOX" tab and go to the Game files on the drive and go to the Dragon Age 2 list open it and delete every game save from that character, once you do so the character disappears from the save list. it is a PITA but such is life. I did that when i wanted to start my mage over again turns out the spirit spells are not as great as i thought. it is actually a little hard to get the walking bomb to go off! lol
Oh the other option is to move any characters you don't want but may want to use again to another storage device. Like a USB drive or if like mine the 4 gb drive. I got a slim when no 250 gig drive ones were on the shelves around here before Xmas so got the 4 gb plus bought a 250 gb drive for the same price as a 250 gb would be. So I move mine to the 4 gb drive that I won't use.