On your iPhone...tap the "Phone" icon. Once you've done that it'll open the app...on the bottom row you'll see 5 options, Favorites, Recents, Contacts, Keypad, & Voicemail. Select Voicemail. Once you do you it'll take you to the voicemail section of the Phone app. At the very top on the left side you'll see "Greeting". Tap on it and it'll give you the option to create a customer greeting or use the default. Select custom, record your greeting, and click save. That's it. Feel free to chime back in if you have issues.