hello all, I have what appears to be gold plated shower fixtures which kinda looks very cheap because it is flaking off. it is a one handle control fixture with the diverter button just below the handle. I would like to change it so that the diverter is in the spout. I'm assuming all I would need to do is replace the present cartridge with the new one and attach the new fixtures. am I correct in assuming this, or is it more complicated than this? thanks