Simply follow the instructions in this link:
@CM22, it's quite an easy process. Follow the steps in the link Dave has sent and you should be good to go. Once you've successfully set up voicemail, you'll be prompted to set up a PIN and greeting. You'll also have the option of setting the number of rings before the call diverts to voice mail.
You can increase and decrease the amount of time it takes for a call to be diverted to voicemail. Just follow the steps below:
If any other questions come up, please let us know.