In regards to the difficulty of R/R tragkorb cases, I found this on the BMW MOA forum from 2003.
1. Open and unlatch bottom latch.
2. Lift up and tilt bottom out.
3. Slide back a little. (Lifting the back of the tragkorb makes it easier to remove from the rack)
It will come right off. Putting back on is the exact opposite.
I add the "lifting the back ..." as it sure makes it more friendly to those who seldom remove/replace tragkorbs. I also added a silver mark from a Sharpie on the top of the rack at just the right placd so once I am ready to install, I position the tragkorb clamp onto the rack, with the back slightly elevated. Works like greased butter.