Atop of shower that connects to goose neck

Not sure what "shower bar" is. Can you be more specific ? Or post picture of it ?

Back to you

Milo

Is a "head piece" the shower head? Majority screw off, some are integral with the neck and unscrew at the shower riser connection.

Screw off would most likely be your best bet, but a picture would be appreciated.

I am with Milo and Questionair please show us a picture, Thanks.

John