You will need 12 pcs 5x3 mm cylindrical magnets to assemble the frame:
- push 4 magnets to the holes at the corner of the frame
- cover the frame with the diffuser material
- put 4 magnets to the corners to fix the diffuser on the frame
- remove the plastic cover pieces from the corners of the YN-300III led light which hides the screws
- push in 4 magnets to the holes on the light's frame
I cut out a piece from a shower curtain as diffuser material.