Yes - you can do them even after the leaves have dropped off, if the ground isn't waterlogged or frozen. Make sure you dig over the area you want to plant them in, preferably incorporating some composted manure or something similar, then wait a week or so for the area to settle before digging a hole and planting out.

You might have to wait an extra year or two for the fruit, though. Trees often wait until they feel that they have got a firm hold on the environment before they flower and fruit. Usually it's quicker for trees on dwarfing rootstocks, though.