Does anyone have any tips for seamless bow changes, i.e. seamless changes from an up to a down bow & vice versa?

I'm trying with some difficulty to master this particular skill. There are 2 books at my disposal and both have tips for practice. One is "Basics" the other is Gerle's "The Art of Bowing Practice". Maybe I'm missing something but neither seems to be doing it for me.

For instance the Gerle book says that we should be aiming to make it sound like we have an endless bow. OK...no issue there!

Then he says that when coming to the end of an up bow, the upper arm should start moving down while the forearm is still moving upwards to finish the up bow. What now???? My poor arm does not comprehend what my brain is trying to tell it!!!

Part of the problem is probably that I generally learn better when I can see the thing demonstrated in front of my eyes. (Making mental note to bring it up in my next lesson).

If anyone has any tips or has found some online demo that has proven useful I'd really appreciate knowing about it I've had a quick look at Prof V's list of topics and nothing there seems to fit the bill.
thanks !

Edited to add that I have found one Prof V video which looks like it will be helpful; here's a link in case anyone is interested;
http://www.videojug.com/webvideo/how-to-ac...-on-your-violin

Try doing it in slow motion without the bow. You should find that as you get to the heel of the bow, your wrist points left and the fingers to the right (sorry, this is probably a crude description of a subtle process!). See if you can then start moving your upper arm to the right while your wrist and fingers stay in that position briefly then allow them to follow the movement of the arm so the fingers smoothly move towards the left on the down bow. If you get the feeling without the bow you might then be able to do it with it.