trouble with knob cartridge removal

[Mark Ward]

I have a leaky shower head so trying to remove the cartridge in the handle for replacement, I've removed the trim, handle and one brass threaded nut but not sure what to do next? Any suggestions would be appreciated. Thanks

 

[Twowaxhack]

Turn your water off at the main.

Use a deep socket to engaged the hex and rotate counterclockwise.

An adjustable wrench could also be used. I prefer a socket.

 

[Mark Ward]

do you mean this nut, pic attached. can't get it to budge

 

[Twowaxhack]

Yep