The easiest way is not to remove it from the duvet.
LOL, Dru! It was new! (WAH!)
The secret to putting a comforter into a duvet is to use two diaper pins. Scootch-up the duvet like a stocking leg, insert a corner of the comforter, and pin in through with a diaper pin to hold in place, then do other top corner. Next, if you are home alone, stand on your bed, holding the two corners with pins and shake the blasted thing down, then flip the end inside. remove pins. done
Jan, is that you? Thanks for the tip! I'll definitely try it next time (ugh--already not looking forward to that!).