Hi
Google should be your friend and you will find a lot of information there
as a starter
https://learningportal.juniper.net/juniper/user_activity_info.aspx?id=8996
a learning byte on setup of NAT64 with DNS64 on Juniper SRX
and there are some more small juniper viedeos on NAT 46 and NAT64
regards
alexander
INDC Germany