The problem is (as I see it) is that it works fine if you originally tagged the answer as official. However the issue I am facing is that another person tagged the answer and I want to untag it. Clicking edit does not allow you to change this (likely because it wasn't by myself in the first place).
You have two options to do this. 1) First delete his answer. 2) Leave new reply with mark as official answer, old one will be untagged.
The problem is (as I see it) is that it works fine if you originally tagged the answer as official. However the issue I am facing is that another person tagged the answer and I want to untag it. Clicking edit does not allow you to change this (likely because it wasn't by myself in the first place).
If you want to change your official answer, you can click edit action link on it. Also if you want to keep history, just click reply [1] link again and enter a new reply, old official answer will be replaced with new one.
You can check/uncheck official answer toggle button [2]