2) doesn't work for horned sheep. You have to manoeuvre the horns back through one by one of they will be knocked off.
Usually by pushing the sheep towards the fence (your legs shoved against it's bum) it enables you to disentangle the horns in peace.
When we were first presented with a stuck lamb, we cut the wires, but after a couple of goes at that we found the pulling the vertical wires apart trick.
ps once they have been stuck a couple of times, horned lambs learn to manoeuvre their own horns out of the square, hyper intelligent Hebrideans do anyway
Another comment about sheep mesh fences. Never have the mesh double or you can never get a sheep's head out and you may well have a hanged animal. We found that out the hard way!