How to Delete BF3 Battle Log Acc?

Before, i made a battle log acc for pc, since i tried playing on it. I lagged like hell so i decided to get a 360 and play the open beta on it. Unfortunately, i made another battlelog acc using my live mail. the old acc has my gamer tag, but i wanna put my gamer tag on the new acc and i need to delete the old acc. Any idea how?|||Your old BF3 on you pc was probably on steam from my understanding. You have to start a new.