You can also get his book "HOLD IT! You're exercising wrong!" on half.com
It carries the entire exercise regimen from the "Escape Your Shape" program. Originally it was about $11.95. On Half.com you should pay considerably less.
I, too, have problems with my knees (I'm an hourglass with most of the sand in the bottom
) and the book I had let me use a bicycle instead of the jump rope.
Good luck to you!