My question was closed as "non-constructive", so I asked it in other place (Freenode) where I got the answer which I want to add to superuser.com.
What should I do?
Edit the question, including the answer as section of the question itself;
1b. "Re-brand" the question to suit the answer more + include the answer into it;
Vote to reopen, then add the answer normally;
2b. "Re-brand" the question and vote to reopen
Add the answer as comment to the question;