Adoption of close relative child

Hi, we are a married couple. Female aged 30 from China and male aged 47 from Sweden. We have a 5 year old son who was born in China. We are now living in Sweden since 3 years. The female has a brother in China and he was married and got a son who is 2 years old now. The marriage didn't work out and he is struggling to take care of the son together with grandparents because the kids mother don't want to have anything to do with them. We would like to adopt this child as the future is not very good for the kid. Any ideas on now to proceed?