how to apply note correction to the header sections in class

Hi Experts,

When trying to apply the notes correction for the SAP note 2164303, there are some corrections that are to be made in the public and private header section of the abap class CL_HRESS_AS_HOLCAL. I've already applied for the corresponding access key, however, when I try to make the required changes to the header section, the 'Display<-> Change' option is disabled.

While we have difficulties and time constraints to actually applied support packages up to the corresponding level, we have to apply the note corrections manually, appreciate if some hints can be provided so I can proceed with the notes application.

Thanks,

Francis