Connect existing VMs to same Cloud service

Hi there, 

i have 4 virtual machines created using quick create option in azure portal (3 cent os and 1 windows).

Each virtual machine belongs to four separate cloud services. For some reason i need to enable inter VM communication and i came through this article ( https://www.windowsazure.com/en-us/manage/windows/how-to-guides/connect-to-a-cloud-service/ ).

• Is it possible to convert existing VMs to single cloud service without losing existing data?
• If yes please guide me the steps .

Thanks In Advance,

Ichanical