As the Title says: Is this possible and if so does anyone know the procedure?

I am the true biological father but the name on the Birth Certificate is that of the (Thai) mothers actual husband at the time, the child is now 10 years old.

Patrick

If the mother was married at the time of birth it doesn't matter. He is the legal father and not you. He had one year from birth and maximum till the child becomes 10 years old to change that.

The child might be able to renounce the father as his, opening the way for you to be recognised as the father.

EDIT:

See section 1536 and following of the Thai civil code, book 5.

http://www.thailawonline.com/images/thaicivilcode/book%205%20title%201-3%20thai%20civil%20and%20commercial%20code%20.pdf