Changing Announcement without using the portal

Hi, I have a client who has an activity line where, depending on the weather, they may or may not have that activity at the facility that day. They want the ability for two different employees to change the recorded announcement (no voicemail on this extension) on the fly, as things change. These users do not want to have to login to the portal to do so but would prefer to change the announcements by phone. Is there a way to do this?