Kyocera p6021cdn, Kyocera FS-C5150dn 7401,7402,7403,7404 error code fix it! HD

Remove the developer unit:https://www.youtube.com/watch?v=hvt9_rpgO18Kyocera p6021cdn, Kyocera FS-C5150dn 7401,7402,7403,7404 error code fix it.