My answer to a question (Asymptotic expansion of $\sum\limits_{n=1}^{\infty} \frac{x^{2n+1}}{n!{\sqrt{n}} }$) was accepted. But it turned out that it was wrong. A comment to my answer later gave the correct result. How can I (1) withdraw my wrong answer and (2) give the author of that comment the chance to submit the comment as an answer and thus get the upvotes and reputation he/she deserves ?

1$\begingroup$ In short: the commenter can always post an answer. You cannot delete an accepted answer unless the question owner unaccepts it. Points cannot be transferred (except you set a bounty on the question and award it to the commenter when they post their answer), but people can vote up the new correct answer. $\endgroup$ – Stefan Kohl♦ Mar 31 '17 at 13:17
Stefan's comment is correct. You can always remonstrate in a comment below your answer or below the question, asking that it be unaccepted because you think it's wrong. Probably that's not necessary here since I've just left a comment asking the commenter esg if he or she could write up an answer based on those calculations. The OP will see that comment, and may decide to unaccept the answer (and accept esg's answer if it gets written up), but only time will tell.

1$\begingroup$ One hack is that the moderators can delete and undelete the question, thus force it to be unaccepted again. $\endgroup$ – Asaf Karagila♦ Apr 1 '17 at 20:14