On your Android device, open the Google Voice app .At the top left, tap Menu Settings.In the Voicemail section, tap Voicemail greeting.Next to the greeting that you would like to use, tap more Set as active. To change your voicemail greeting: Go to Phone > Voicemail and tap Greeting. Then follow the prompts to change the greeting. To change your voicemail password: Go to Settings > Phone > Change Voicemail Password and then enter the new password you want to use.
On your iPhone open the phone app. Tap on the Voicemail present in the bottom right corner of your screen. Click on a voicemail. Click on delete. If you want to remove a Voicemail from your device permanently then you have to perform a one more set of steps. On your iPhone open up the phone …

You will be asked to delete your current Voicemail greeting. Click on the ‘Yes’ button that appears on the screen if you want to remove that. You can save your new recorded Voicemail greeting or can use the default recorded option. Wait and hear the new Voicemail greeting message that the instructions speak out. If you want to keep that recording as your Voicemail greeting, then save it. Or you can re-record the message to get a different greeting.
To change your Standard Voicemail greeting follow the directions below. Enter your password and the press # key. From Shoretel Communicator (You will need to have access to your Shoretel phone to record the message) In the menu bar, click More, then Prefereces. Your phone will turn on and beep. Begin your message.