Kyocera FS-C1020MFP - Manual (Page 78)

Lift out print cartridges and shake them from side to side. The black print cartridge
comes with a protection sheet that you must remove before shaking.
Carefully lift out the print cartridge vertically, holding its center.
Place the black print cartridge on a flat surface and remove the protection sheet before shaking.
Shake each print cartridge from side to side five or six times.
Check the toner color and corresponding location, and then carefully insert the print
cartridge vertically.