Yes, but there are many factors to consider first. You would need to consult a structural engineer to provide a report detailing the size of the steel beam required to support the remaining breast above. If the chimney was on a party wall then the party wall act would come into play, if the building is listed then you may require planning permission, even if the building isnt listed you would require building control inspection and regulations. To carry out the work you would have to insert steel acrow props with strongboy additions, and strut the upper stack securely before touching the stack to be removed. Once the brickwork is taken down, a steel rsj beam is inserted onto padstones, packed up tight with slate and cemented in place. This takes the weight of the remaining stack(s).