How is this shower wall outlet removed?

[Come on Dave]

Hi, this is the wall outlet of an old Mira Excel mixer shower. I need to remove it, so I can re-tile the shower. Can anyone advise me how the plastic elbow is removed? It will rotate freely, but not unscrew. It seems very resistant to simply being pulled straight off. I want to re-use it - I am not changing the shower as it had a new cartridge quite recently. The tiles are not actually mosaic - they are a mosaic effect on a solid 300mm square tile. Any thoughts would be appreciated.

 

[RandomGrinch]

The part looks like a Mira Response RAC outlet elbow. The following pic might give you an idea of how it disassembles!
https://www.showerspares.com/search/mira-response-rac-outlet-elbow-mounting-pack-411.22/

 

[Come on Dave]

Many thanks for that Random Grinch. With that info I have found some fitting and disassembly instructions which is just what I needed. In case it helps anyone else, its on pages 16-18 of this document Mira Response Power Shower Fittings Installation & User Guide 2.1605.181 (plumbworld.co.uk)