BellaBoo -
http://youtu.be/oaZAxXXOpAo
As to the issues of the tension setting jumping around, there's another thread here somewhere that addresses that. Littledentist found out that the presser foot has to be down in order to set the tension and have it stay. To be honest, I've not changed my top tension in quite a while and can't remember if the presser foot was up or down when I did it, but hopefully this information will help someone else.