how to get rid of pampas grass

chop back as much as you can, protect your hands because the long leaves have razor-sharp edges! Then, after a dry period set fire to the middle of the plant, and keep centre burning for as long as you reasonably can (basically have a mini-bonfire in there), supervising it carefully.
After that, dig out the stump and root.

Brilliant demolition job, at least I thought so, enjoy : ) !

I live in London and what Weeding suggests is verboten - no bonfires like that allowed. It is possible to dig it out, having removed as much of the top as possible, but it is hard work - I speak from experience!

that's true bamboo, we are lucky to live in a no-restrictions area. Our council is too busy making a hamfisted job of everything else to even get round to meddling with bonfire bylaws. If fires are not allowed in your area, suggest very sharp knife to cut out all growing shoots before attacking roots?

If bonfires are banned, are smoking and bbqs exceptions which are allowed?
I think I'd mind the niff of frequent bbqs much more than bonfires, but then again, I am a bit weird.

I found the easiest way was to give my son and his friend a fork and a spade, go indoors for a cuppa and return when they had done all the hard work!!