Hi there hope i can be of assistance.
Ok first remove the driver side fornt wheel, then remove the inner wheel arch trim.
Then with a torch, you should see a small black box on the engine side.
Flick this box open with a screw driver and you shoudl see 2 cables in there. With some pliers pull on Both cables, while an assitant tries to lift the bonnet.
This will open the bonnet.
There isnt alot of space so this will be a little awkward.
Its likely the cables from the black box, to the bonnet latch itself need replacing, these are a very common fialure on the 75/ZT.