Part 1: Steps to deregister iMessages on your iPhone
Part 2: Deregister iMessages without iPhone
Part 1: Steps to deregister iMessages on your iPhoneStep 1. Turn off iMessage
If you have your iPhone with you, you can go to "Settings" - "Messages" – Turn Off "iMessage".
Step 2 Turn off FaceTime
After that, go back to "Settings" and you will find "FaceTime" just below the "Messages" app. Tap it and you will see the next screenshot. Just turn off "FaceTime" and that's it.
Part 2: Deregister iMessages without iPhoneYou can also deregister your iMessages even if you've sold your iPhone or your iPhone doesn't work at all now.
Step 1. Go to Apple Deregister iMessage Page
Get to the self-solve page for deregister iMessage page of Apple Inc. as shown below: https://selfsolve.apple.com/deregister-imessage.
Step 2. Enter your phone number
Then, you will see the below interface asking you to enter your phone number to get the code. Choose your country first. And type in phone number next to it. Then, click the blue "Send Code" option on the right.
Step 3. Enter confirmation code
Enter the 6-digiet codes you received on the below blank. Then, click "Submit" when it's done.
That's it. After that, the phone number has successfully deregistered iMessages, and you can now receive messages no matter it sent from iPhone or iPad on your Android phone. If you have other problem while using Android/iPhone, please feel free to contact us, we will always be here for help.