Complex sentence: Alex travels to Bangkok where Ash explains their plan; he and Alex will take on the identities of Afghan refugees who have paid the snakehead to smuggle them into Australia, in order to identify important members of the snakehead and find out how they smuggle the refugees.
Split into simpler sentences: Alex travels to Bangkok where Ash explains their plan; he and Alex will take on the identities of Afghan refugees who have paid the snakehead to smuggle them into Australia. In this way they can identify important members of the snakehead and find out how they smuggle the refugees.