How do you replace the diverter for the bath tub and shower?

how do you replace the diverter for the bath tub and shower?

There are two types of diverter spouts. Slip on and threaded spouts, (see images) Look under the spout next to the wall. If there's a small opening then you have the slip on type. If not then you have the threaded type. Get back to me with the type of diverter that you have and we'll go from there. Regards, Tom