I have a 2 handle shower faucet with a the diverter valve for the shoer/tub in the center. Water leaks from the tub shput when the shower is running so the diverter is leaking. I’m not sure what kind it is but it is old and made of brass. I have taken the handle off the diverter and removed the packing nut but still can ‘t remove the valve stem. Does it unscrew or just pull out? Is there a specail trick to removing the valve stem?