Mira 439.77

 The replacement isfairly straightforward.

Turn ofthe water and power you then have to dismantle most of the inside of the showerto get enough space to slip the old part out and the new part in.

This sounds more difficult than it actually is, however youdo have to be methodical noting where screws/nuts etc. come from and what goeswhere and it is always a good idea to take photos as you go because you canrefer to them when you are rebuilding.

Absolutely correct, replace the flow regulator