Well haven’t done it in sometime, but from what I remember its pretty easy, but not very fast if you were to do a lot, I think there is a software way to do this on a computer, but I don’t know that for sure either. It is however easy enough to save them on the unit and transfer them to the other unit.
If you want to transfer all the way points buy and data disc and download from the old one and upload to the new one. That way you will also save all your existing way points, which is a good idea anyway.