I have a bad back and use a thule extension arm. You put one side up on the extended arm and then pick the back up. You can easily fabricate one for your rack that either mounts to the outside or slides inside the ladder rack if the crossbars are hollow (had one like that also when I had a truck shell).
Came across this site, at the very bottom you can kinda see how it works in action.
http://images.google.com/imgres?imgu...a%3DN%26um%3D1