Your kickstand has 2 curved arms that fit tightly in the pockets of the raised area on the back of your device.
These arms have a notched side and a round side. The notched side of the arms should face "upward" towards you, like so:
To install a kickstand, start on one side, pushing the curved arm into the case's side pocket. We recommend keeping the kickstand as parallel to the back of the device case as possible, since the pocket holes are also fitted with the same half moon shape.
After inserting one side, pull/stretch the kickstand across the raised middle area to the other side. Be sure to keep the kickstand as close to the case as possible, but not directly touching it, otherwise you may scratch the raised middle area with the 2nd arm's sharp edge.