I found one of these invaluable along with a set of single hex sockets
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F182133925456
I removed the whole strut and then attacked it with penetrating fluid and a hammer to get the pinch bolts moving. You've...