How extensive?
It depends on how extensive the damage is. The bulkhead is plywood and, if the damage is limited to dry rot at the bottom edge it's unlikely that there is significant structural damage. In that case, you could cut out the damaged part and sister in an oversized replacement piece of marine teak plywood, screwed and glued to the existing bulkhead. If the repair shows on the saloon side, creative use of molding could cover any cracks.