This is quick and easy, head over to https://selfsolve.apple.com/deregister-imessage/ and fill in your mobile number. It will then SMS a code which you need to input into the site and then deactivate iMessage for that number.
How to De-Register iMessage
This is quick and easy, head over to https://selfsolve.apple.com/deregister-imessage/ and fill in your mobile number. It will then SMS a code which you need to input into the site and then deactivate iMessage for that number.
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