We always found that feeding veg by hand was a good way of winning ours over. We also waited until they were feeding, then gently rubbed their backs, bit by bit. Just take it easy, they will soon start to trust you. It is nice to sit with them too for a bit, get a bale or crate and just let them discover you.
They don't like their bellies being touch so much by the way, but they will soon get to love a good back scratch.