At position punctuation after a box I asked how to reformat punctuation that (as it turns out) is correct as is. There's an answer to my question as asked which I've upvoted. It doesn't seem quite right to accept it, but I don't want to leave the question without an accepted answer. Deleting the question destroys information someone might find useful some day.
You have a few choices:
Delete the post entirely;
Post a comment to the current answerer asking to amend their proposal to suit your needs;
Provide your own answer;
Post a bounty to solicit answers that may be more betterer... :)
Here are the options based on the above choices:
You can't, since the answer has a positive score. See the FAQ How does deleting work? What can cause a post to be deleted, and what does that actually mean? What are the criteria for deletion?.
This is somewhat contained in the answer already, but not explicitly. Suggesting to be a little more explicit and include others' comments in such a statement might make the answer suit your needs more.
In some cases this is completely viable if your answer differs entirely from others. It may be awkward to grab that opportunity from someone else, but there's no guideline suggesting it can't/shouldn't be done. If you feel a self-answer will better-answer your own question, fill your boots.
In this case it may be a bit extreme, but it's still an option for the non-rep-hoarding-kind.
Another totally acceptable choice. An upvoted answer to a post removes it from the list of unanswered questions (...the criteria there being "questions with no upvoted or [no] accepted answers").