Shining Aquas had found a way of editing old posts in an absolutely brilliant (and non-intuitive) way. I'm copy-pasting his technique in the main forum so that everyone can see it.
First of all, all of this clearly works only on your own posts
1) Find the post you want to edit. Right click on the "Quote" icon and select "Copy Link Location". This will give you a long url. For example, you can get something like this:
2) There are two changes you need to make before going to the above address. Find the word "responder" and change it to "editar". Additionally, take the very last "c" in the address and change it to a "m". The result should look like this:
3) Enter it into your web browser and everything should work out.
After the FAQ released, that's the biggest news of the century
Thanks again to the friend who cracked this, and enjoy