They'll come right, spend plenty of time with them, be quiet, feed them regularly not that they need it but they are inquisitive and love a free meal!!, we have a lot of cattle and they are all used to one person, namely me!! If I go in the field with anyone else they react differently. I bought a neighbours herd a few years ago, and they where wild believe me, all he had every done is chase the round with his quad and tractor, they where that bad one vet refused to Tb test them, everyone thought I was mad, when I got them home, I turned them out, put a feeder in the middle of the field, fed them every day, well I never saw them for the first three days but the feed was always gone in the morning, I never use a tractor or a quad to look at any on my stock, yes I use it to get to the field then leave it there an walk the rest of the way in. Now they are like babies they follow me anywhere I cant shake em off, they are all on there 3rd calving and have mixed in perfectly well with all the others. If you winter them in they will calm down a lot, as they cant escape and will see you and get used to you everyday. Don't worry about movement laws for now, and nobody can shoot them unless they go totally ape and kill someone and by the sound of it they are far from doing that.. Just take your time and good luck...