Trying to change night ringer voicemail

Ok. You will have to find someone who has access to system manager, or has system manager rights for their mailbox.

They will then be able to select System Manager Options, then Change the Greetings. It will tell you which mode you are in, and ask you if you want to change to Holiday Mode. The responses are 1 for YES and 2 for NO. Say no to Holiday Mode, and then it will go thru Day Mode and then Night Mode, playing each one first then asking if you want to change it.

If you must call in a service order with your phone system vendor, make sure he/she not only assigns someone's box with manager access, but also creates a back-door box with manager access. This way you won't be messing with the original Manager Box. It gets expensive having NEC decipher the Manager's password if it gets changed and no one remembers it.