How to change iMessage phone number?

hi

i have iPhone 6s 64GB with iOS 9.3.5 but I change my phone number.

Now I want to change old phone number to new number in iMessage. I disable iMessage and change my sim cart and active in in my cell phone, and then active iMessage but my new number not work on it.

please help me how to do it.

Thanks lot for your contribution.