May I know how do you change formula from nan 1 to nan 2 ? I tried to change but lo don't like so I mix the two formula till now I giving him 4 scoop nan1 and 2 scoop nan 2 , how can I totally change to nan 2?

Reckon you're on the right track. Mixing the two and gradually reducing the proportions of Nan 1 and increasing Nan 2 will make the transition easier. Keep doing this till its just Nan 2 and eventually baby will stop rejecting it :) Good luck!!