When I get wild/scared animals, I just go in with them and sit quietly.
Don't look at them (we have predator's forward facing eyes, very scary for prey animals). Move extremely slowly. Put some 'goodies' out, (I use sultanas) initially neither near you nor near them. They'll find them eventually. Hopefully associate you with the goodies.
Even when they come to you, don't look at them. Let them sniff you and don't try to pet them. Just talk very quietly in a low voice. Eventually let them sniff your hand. Best place to pet, once they're totally comfortable coming up to you and hanging around you, is their chest between their front legs. They like it to be scritched and it's a non-threatening move, unlike a hand near the head.
It can take a while but it's one of the best things, when a scared animal comes to trust you