We see gangs pinch material, going for radical alterations (8,7)

I believe the answer is:

sweeping changes

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'going for radical alterations' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'we see gangs pinch material' is the wordplay.
'material' indicates an anagram (the letters provide the material for a new word).
'we'+'see'+'gangs'+'pinch'='weseegangspinch'
'weseegangspinch' is an anagram of 'SWEEPING CHANGES'.

Can you help me to learn more?

(Another definition for sweeping changes that I've seen is " Wholesale new arrangements".)

I've seen this clue in the Sydney Morning Herald.

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