Hello Red!Hi mate!
We have the opposite issue here. I uproot & burn fifty elder trees a year -they really are a weed tree here. If you get them under 6" they should transplant easily. After that it would be tricky to get the root ball intact. I would just put 20 or so ripe berries in a 3" pot of compost (repeat as required) and put somewhere warm. Keep them damp, they should germinate.
I don't have to protect berries but the trees respond really well to coppicing. Hack them down, make them multi stemmed & net them. That should protect the berries.