Call your friends and tell them that they have to call you immediately because you have the most unbelievable story to tell them.
Then leave a voice mail message on the phone that sounds like this:
Hello,
Hello,
Is Anyone there?
Hello,
I can barely hear you. Can you speak us?
Hello, hello
Louder, please louder
Is this (say a friends name)? Are you there?
Of course on the other end of the phone, your friend is talking louder and louder trying to be heard because they want to know the big news.
Then say -- Hope you enjoyed my April Fool's joke. Talk to you later.