It is virtually impossible to change (see Change username/name on the bitcointalk forum), and it would entail paying 50BTC to become a VIP member to get the job done.

Since your account is still a Newbie with not much activity and not already tied to business (at least that I could see), consider creating a new account with the correct name and using that one instead. You don't have to delete your current account. In fact, you can't delete an account. At best, you can try to delete the posts (not all may be deletable, depending on the board you posted them in) and perhaps create a small post in off-topic that states which your new account is with a link to it, in case any person following your account wonders where you’ve gone off to.