1) On the back of the EZ-Pro Beauty Dish, unscrew the thumbscrew (and its washer).
2) With a Phillip's head screwdriver, unscrew the adjacent screws on either side of the thumbscrew's position (circled in red).
3) On the posts provided with the reflective dish, remove the two Phillip's head screws, circled in blue (with a screwdriver, or with your hands).
4) Place the insert you have received in the ring on the back of the EZ-Pro Beauty Dish, ensuring the edge of the insert is beneath any washers that are still on the back of the beauty dish.
5) Using the longer Phillip's head screw from the posts and the washers from the short screws, screw them back into the back of the beauty dish using a Phillip's head screwdriver (shown in green).
6) Replace the thumbscrew and its washer to its hole on the back of the beauty dish.
7) After flipping the beauty dish over, screw the posts onto the protruding screws (circled in yellow).
8) Remove the thumbscrews at the ends of the posts (circled in cyan).
9) After placing the reflective dish over the holes on the posts, screw the thumb screws back into the posts.