Replacement Diverter Assembly with brass shaft including black rubber seal, chrome screw-in section, spring, threaded hose connection, and new control knob.

To Replace this diverter:

1. Unscrew the diverter control knob on top of the spout, then carefully unscrew the chrome section of the diverter that attaches to the spout. The spring, if there is one as some models don't have one, can then be removed. Then unscrew the shower hose threaded connection underneath using a large Allen or Hex key. Sometimes a large flat sided screw-driver will also work. 

2. The whole brass shaft should then come out of the underneath side. Please check that there is a black rubber seal which fits into the groove near the base of the brass shaft. If it is missing it could well be inside the spout. Sometimes it finds its way behind the mesh bath outlet. This can also be unscrewed using the two flat side sections, if necessary. 

3. Insert the brass shaft from underneath, re-attach the threaded shower outlet, replace the spring, chrome section and then the control knob.