I rake out the dead bits in the spring, and also cut back the flowers then - they're quite decorative in the winter months. No, you don't need to cut back the green part, Pampas grass is evergreen. I'd mulch and feed it in the spring.

I'd recommend leaving it alone now, as Spritz suggests above, but next March, get out there with a thick jacket, gloves and a pair of goggles or glasses and hack the whole thing back to the centre, all the leaves, removing the spent flower heads by cutting them right at their bottoms, and then rake out the centre. Do that every year - that's a small space for a pampas, they get pretty big.

Thanks for the advice. Would it be okay for me to now remove the straw coloured parts? They are very loose and just come away in your hand. In fact when the wind blows strongly it often blows bits of it over my garden.

Remember that the 'loose stuff'will protect the plant during the winter, so if you can bear to leave it and pick the bits up, then do.

I'd remove any loose bits myself, and by that I mean if they come away easily from the plant when you pull gently. Saves waiting and collecting the bits when they fall off.
Hopefully that's a dwarf form of Pampas...

The reason I'm being cautious about it is that I almost lost my plant last winter, so I'd still say leave some in the crown in case of prolonged cold.

Anything that's really loose will be blown off anyway, Spritzhenry, all over the garden, and if its not really loose, shouldn't be removed, particularly if its little, loose bits in the crown of the plant, as you say. But frankly, that's not a good place for a pampas grass, is it, really - I've been hesitating all the way through this thread about saying take it out now, talk about wrong plant, wrong place...

True. I looked to see how much soil was visible around it, and it looks tight. The Lavatera next to it is also in a confined space - and protruding across the pavement!