We changed the instructions from
(3) Copy the "bin" folder from this hotfix to your <WebHelpDesk> folder and rewrite all files.
to:
(3) Copy the 'PushNotificationProductionCertificate.p12' file from this hotfix to your <WebHelpDesk>/bin/webapps/helpdesk/WEB-INF/Helpdesk.woa/Contents/Resources/ folder and overwrite the old file if asked.
Also we modified the content of this HF. Change will be published soon. Thanks guys for pointing this out!