Add/remove classes from items (database)

[Nydosa]

I am hoping someone can help me figure out an easy way to either add or remove a class from the bitmask 'classes' in the items table. Is there another way of getting Navicat to look and edit classes based on the bitmask?

For example, how could you add 'warrior', =1, to every item, but exclude the one it's already on?

I'm trying to avoid making items all/all here, even though that would be much easier.

Thank you!