Yzyz

My Thai ex wife and I divorced last year at the amphur in Bangkok. It was stated in the divorce paper that we shared custody of our 6-year old child. I have been taking care of my kid happily and we are now not living in Thailand. Mother is fine with it and she does not want to have much to do with us. I have been wandering if it’s possible to change shared custody to sole custody. What should I do ? Anyone has similar experience ? Thanks a lot.

Can the consent letter be used repeatedly or each time child goes abroad, need a new one ? Thanks.