There are some dangers associated with this and since I've never been in this situation before, I can't say for sure what effect it would have.
But, if I was in this situation, I would consider doing a search and replace directly in the database table holding the threads. Obviously do an entire backup of your system before trying this.
If you're running MySQL here's how to do it:
http://www.mediacollege.com/computer...d-replace.html
I think the correct table in the vB database is 'post', and the field you're interested in is 'pagetext'. I'd run two queries:
update post set pagetext = replace(pagetext,'[VIDEO]','[CUSTOMVIDEO]');
update post set pagetext = replace(pagetext,'[/VIDEO]','[/CUSTOMVIDEO]');
replace CUSTOMVIDEO with whatever you want your new tag to be.
Like I said, backup, backup, backup (especially the database). I have no idea what effect this will have.
By default, MySQL should be case insensitive, but make sure just because you want one query to match [video] and [VIDEO] without having to worry about case sensitivity. You can find out more about that here:
http://dev.mysql.com/doc/refman/5.0/...nsitivity.html
Anyways, the information is provided AS-IS with no warranty or liability. Good luck.