If the return was filed successfully then make the fix next year ... FYI the IRS only looks at the first 4 letters of the last name ... the rest of it could be dead wrong or missing and the return will still process just fine.
If the return has been rejected then you can make the correction and resubmit the return. However if this was not your error, and the IRS is not accepting the name as written on your SS card then follow the advice in the prior answers to correct it at the source.
