The guide section of the forum offered me no help when I was looking for information on opening the bonnet with a snapped cable, but it is very simple, and as for people asking for money for the solution on here, well that's just cheeky.
Just jack the car up, and stick your hand up behind the radiator and feel for the cable sleeve. The sleeve works in the opposite way to the cable so you need to push it towards the catch for it to release. It should open, none of that cutting holes in bumpers or smashing bonnets lark
. Simple.