There is a spring clip in each corner of the fridge duct. Gently push them towards the center of the opening, and then towards the fridge.
There are 4 clips but only 2 are shown in the picture. (I forgot to take a picture after removing the right angle duct, so just imagine it's gone and you can see the other two as well. Please take a picture and update this page.)
Close the freezer door and head to the fridge side. But first, if your helper dropped ice down the back of your shorts in the prior step, feel free to return the favor.