Hi there, I've had a similar situation where I needed to replace
[ATTACH type="full"] with
[ATTACH] in almost all of my XenForo articles that had an image.
To do this, I used the following query through PhpMyAdmin:
UPDATE xf_post SET message = replace(message, '[ATTACH type="full"]', '[ATTACH]')
In my case, only the
xf_post table was involved.
However, I'm not sure what you need to replace or in which table it is located.
In any case, you should be extremely cautious when modifying things in the database and I recommend you not to do it yourself, but to hire an expert to help you.
I just wanted to share my solution and I don't want to encourage you to do the same.