I am filing out my 8949 entries via the easy question and I can not get the explanation code to match my 1099-B.

I am filing out my 8949 entries via the easy question and I can not get the explanation code to match my 1099-B.  Worse the codes appear to be adding on each other.  How can I remove the old codes?  How can I enter them to match the 1099-B?